CN116916985A - Pulsatile flushing of medical devices - Google Patents

Abstract

A system for flushing a lumen of a medical device to remove air, the system comprising: a first fluid delivery device adapted to provide a pulsatile flow of a flushing gas from a pressurized source of the flushing gas; a second fluid delivery device adapted to provide a pulsatile flow of the flushing liquid from a source of the flushing liquid; and at least one fluid coupler for connecting the first and second fluid delivery devices to the lumen of the medical device.

Description

Pulsatile flushing of medical devices

Background

If the gaseous volume enters the blood stream, surgery to intervene in the vasculature in communication with the brain vasculature may expose the patient to risk of brain injury.

It is standard practice to flush the medical device with a flushing fluid (such as medical grade saline) prior to intravenous surgery to displace air from the medical device in order to reduce the risk of air entering the blood stream.

In EP 3 367,978 A1, it is proposed to flush the stent graft using a multi-stage flushing method prior to inserting the stent graft into the patient in order to remove air from the stent graft. The first stage involves flushing the stent graft with a fluid, such as carbon dioxide, to displace air from the stent graft, and the second stage involves flushing the stent graft with a solution that preferentially absorbs air, such as a perfluorocarbon solution or a degassed solution.

While such methods result in improved air removal from medical devices, the hazards posed by even extremely small volumes of air mean that there is still a need for improved air removal methods and systems.

Disclosure of Invention

According to a first aspect of the present invention there is provided a system for flushing a lumen of a medical device to remove air, the system comprising: a first fluid delivery device adapted to provide a pulsatile flow of flushing gas from a pressurized source of flushing gas; a second fluid delivery device adapted to provide a pulsatile flow of irrigation liquid from a source of irrigation liquid; and at least one fluid coupler for connecting the first fluid delivery device and the second fluid delivery device to the lumen of the medical device.

The inventors have recognized that flushing the lumen of a medical device with a pulsed/pulsatile flow of flushing fluid increases the efficacy of air removal during the flushing process. In conventional flushing techniques, the flow of flushing fluid is laminar, meaning that the closer to the inner surface wall of the lumen in which the fluid flows, the slower the fluid flow rate. At each surface, an infinitesimal layer of rinsing fluid does not flow (i.e., it has zero velocity), which reduces the effectiveness of the rinsing. This is especially problematic when bubbles remain and accumulate on the inner surface wall of the delivery system lumen, on the outer surface of the implant contained within the delivery system lumen, and between the outer surface of the implant to be delivered and the inner wall of the delivery system lumen, as these bubbles are difficult to dislodge when using a laminar flow flush.

Pulsed flow disrupts the development of laminar flow and brings the velocity profile closer to that of turbulent or plug flow. The higher degree to which this effect occurs further increases the velocity of the fluid near the surface. Thus, pulse flow increases the effectiveness of flushing in areas where flushing difficulty is greatest.

As used herein, the term air is understood to mean invisible gaseous matter surrounding the earth, which is primarily a mixture of oxygen and nitrogen.

Preferably, the first fluid delivery device comprises a flow restrictor actuatable between an open position (in which the flushing gas can flow) and a closed position (in which the flushing gas cannot flow) so as to pulse the flow of the flushing gas.

Optionally, the first fluid delivery device may include a compression element configured to compress a flexible tube coupled to the source of flush gas at predetermined time intervals, thereby restricting the flow of flush gas through the tube. This arrangement allows the fluid delivery device to use off-the-shelf connection tubing and a source of flush gas.

The compression element may be reciprocally movable, such as by a solenoid motor.

Alternatively, the compression element may be a rotatable cam.

Alternatively, the compression element may be pneumatically drivable. For example, the compression element may be configured to operate as a pneumatic reciprocating circuit. The purge gas may optionally be used as a source of pneumatic power.

The rotatable cam may be coupled to a torsion spring adapted to drive the rotatable cam (i.e., a clockwork mechanism). This means that the first fluid delivery device does not require a power source, making its use extremely versatile. Alternatively, the compression element may be coupled to an electric motor configured to drive the compression element. For example, the electric motor may be battery or power driven.

In some examples, the first fluid delivery device may include a user-actuatable (i.e., manually-operated) gas control mechanism for providing a pulsating flow of the flushing gas. For example, the first fluid delivery device may include a user-actuatable trigger configured to pulse the flushing gas upon application of an actuation force (e.g., by a user/operator).

The system may further comprise a stand adapted to hold the source of flushing gas in an upright position. The flushing source may be a gas such as carbon dioxide (CO 2). If the CO2 source (e.g., tank) is not held upright, liquid CO2 may be vented from the source, which results in a faster depletion of CO 2.

The stent may optionally include a first fluid delivery device. That is, the first fluid delivery device and the scaffold may be formed as a single component.

The stent may optionally include both a first fluid delivery device and a second fluid delivery device. That is, the first fluid delivery device, the second fluid delivery device, and the scaffold may be formed as a single component.

Preferably, the second fluid delivery device comprises a user-actuatable liquid delivery mechanism (such as a trigger) for providing a pulsating flow of flushing liquid.

Further, the second fluid delivery device may include a user-actuatable positive displacement pump, which may include a compression chamber.

The positive displacement pump may further include a one-way valve configured to allow one-way flow of the flushing liquid from the source of flushing liquid into the compression chamber (i.e., when the trigger is actuated). For example, the one-way valve may be an umbrella valve or a duckbill valve or the like.

Preferably, the positive displacement pump further comprises a one-way valve configured to allow one-way flow of flushing liquid from the positive displacement pump towards the at least one fluid coupler. The one-way valve may likewise be an umbrella valve or a duckbill valve or the like.

The positive displacement pump may include one or more resilient compression members arranged to: resetting the user-actuatable liquid delivery mechanism to an initial position and/or aspirating irrigation liquid from a source of irrigation liquid.

Optionally, the fluid coupler may be a three-way valve.

In some examples, the first fluid delivery device and the second fluid delivery device may be included in a single device.

Alternatively, the first fluid delivery device may be coupleable (or coupled) to the fluid coupler via the second fluid delivery device.

The flushing liquid may be a first flushing liquid and the second fluid delivery device may be further adapted to provide a pulsating flow of the second flushing liquid from a source of the second flushing liquid.

Preferably, the second fluid delivery device further comprises control means for selectively coupling the second fluid delivery device to respective sources of the first and second flushing liquids.

The system may additionally comprise a sterile filter which is arranged or positionable in sequential connection between the first fluid delivery device and the pressurized source of flushing gas.

According to a second aspect of the present invention, there is provided a method for flushing a lumen of a medical device to remove air prior to introducing the medical device into a body, the method comprising: the inner cavity is flushed with a pulsed supply of flushing fluid.

As explained previously, the inventors have recognized that flushing the lumen of a medical device with a pulsed flow of flushing fluid increases the efficacy of air removal during the flushing process. In particular, the pulsating flow improves air displacement and increases the velocity of the flushing fluid near the surface by creating turbulence of the flushing fluid that disrupts laminar flow, thereby increasing flushing effectiveness in areas where flushing difficulty is greatest.

Multiple flushing fluids may be used to flush the lumens in sequence, and multiple lumens may be flushed simultaneously.

While it is preferred that all of the flushing fluid be pulsed when multiple flushing fluids are used in sequence, this is not necessary to improve the efficacy of the flushing. When flushing with multiple flushing fluids, only one of them (preferably the first flushing fluid, e.g. carbon dioxide) needs to be pulsed in order to provide an effect with improved air removal during flushing. However, pulsing more than one flushing fluid may further enhance this effect.

Optionally, the flushing fluid may be a flushing gas. For example, the purge gas may be carbon dioxide. Preferably, the method further comprises flushing the lumen with a pulsed supply of flushing liquid.

Alternatively, the flushing fluid may be a flushing liquid. For example, the rinse liquid may be brine or perfluorocarbon. The flushing liquid may be a pH adjusted and/or degassed buffer solution. The flushing liquid may be a gas absorbing liquid (e.g. a deaerated and/or pH adjusted solution that absorbs air and/or carbon dioxide).

A variety of flushing liquids may be used. For example, a first flushing liquid (such as a gas absorbing liquid) may be used, followed by flushing with brine. One or both of these liquid washes may be pulsed.

Flushing the lumen may include flushing at a pressure above 101.325kPa (also referred to as standard pressure, which is approximately equal to the air pressure at the earth's surface). Flushing at increased pressure improves the ability of the flushing fluid to absorb air.

Preferably, the irrigation lumen includes a pulsed supply coupling the lumen to the irrigation fluid.

According to a third aspect of the present invention there is provided a bubble trap for trapping bubbles entrained in a flow of liquid, the bubble trap comprising: a discharge port for discharging bubbles from the bubble catching means; an inlet port for receiving a flow of liquid; an outlet port; and a fluid conduit coupling the inlet port to the outlet port, wherein the fluid conduit comprises at least one baffle arranged (in use) to alter or agitate the flow of liquid (i.e. through the fluid coupler) thereby separating bubbles from the flow of liquid.

The bubble trap device may also be referred to as an actuation module.

The bubble trap forms a tortuous flow path for the flushing liquid which separates out bubbles entrained in the flow of the flushing liquid so that they can be discharged via the discharge port. When used in conjunction with an irrigation system (such as the first aspect), this helps ensure that all air is removed from the irrigation system itself during the priming process, rather than allowing that air to reach the medical device. Thus, the bubble trap device allows for enhanced activation of the irrigation system by improving air removal during the activation process.

Preferably, the bubble catch means is shaped to direct or transport the separated bubbles towards the discharge port. For example, at least one surface may be angled towards the discharge port in use. That is, at least one surface (preferably the top surface) of the bubble trap may be skewed/inclined towards the discharge port, wherein the discharge port is positioned at the highest point/vertex of the bubble trap.

The baffles may also be referred to as deflectors, flow disruptors, agitators, agitating elements, agitating members, or the like, and may be any member that disrupts, agitates, or redirects fluid flow. For example, the baffles may be ribs, separate components, or molded components.

The purpose of the baffle is to form a baffled path for the flushing liquid through the activation module (i.e. the baffle is arranged to form a baffled path through the fluid conduit). This causes the flushing fluid to be agitated by the baffles, separating bubbles (such as air) from the flow of flushing liquid.

The at least one baffle may be formed of an elastomeric material (such as silicone) or a rigid material (such as polycarbonate). The bubbles preferentially collect on the elastomeric material, thus the use of the elastomeric material as a buffer enhances the separation of the gas from the flushing liquid.

The at least one baffle may be arranged to interrupt laminar flow of the flow of liquid within the conduit.

Preferably, the at least one baffle comprises one or more angled protrusions, such as angled edges or corners. The relatively sharp edges presented by these angled projections further agitate the flow of liquid, enhancing gas separation.

Optionally, the inlet port and the outlet port may be arranged on opposite sides of the bubble trap device, and the at least one baffle may be positioned between the inlet port and the outlet port and arranged perpendicular to a line intersecting the inlet port and the outlet port (i.e. perpendicular to an alignment axis of the inlet port and the outlet port).

The discharge port may optionally be sealable, for example by a discharge cap or the like.

The discharge port may also be shaped to couple to a syringe, such as a vacuum pressure syringe.

Optionally, the housing of the bubble trap device may be formed of an elastomeric material, such as silicone. Alternatively, the housing may be formed of a rigid material (such as polycarbonate).

According to another aspect of the present invention, there is provided a catheter flushing system comprising: a source of rinsing liquid; a pump for driving the flushing liquid; and, the bubble trap device of the third aspect, wherein the inlet port of the bubble trap device can be coupled (or coupled) to a source of flushing liquid.

The pump may also be coupleable (or coupled) to an inlet port of the bubble trap device. That is, both the source of flushing liquid and the pump may be coupleable to the inlet port such that the pump is arranged to drive the flushing liquid through the inlet port.

Alternatively, the pump may be coupleable (or coupled) to the discharge port of the bubble trap device. That is, the pump may be arranged to: the flushing liquid is sucked/pumped into the bubble catching device through the inlet port by applying a negative pressure at the discharge port.

The pump may be any suitable pumping means such as a syringe (e.g. a vacuum pressure syringe) or the like.

The use of a bubble trap in combination with a catheter flushing system allows for improved activation of the catheter flushing system by enhancing air removal during activation.

According to yet another aspect of the present invention, there is provided a method of activating a catheter flushing system, the method comprising: coupling a source of rinsing liquid to an input port of the bubble trap device; opening a vent on the bubble trap; driving a flow of flushing liquid through the bubble catch means and out of the discharge port; and closing the discharge port.

The use of a bubble trap in combination with a catheter flushing system results in improved activation of the catheter flushing system by enhancing air removal during activation.

The flow of the flushing liquid may be driven by a pump coupled to a source of the flushing liquid. Alternatively, the flow of irrigation fluid may be driven by a vacuum source coupled to the discharge port of the bubble trap device.

Drawings

Examples of the present invention will now be described in detail with reference to the accompanying drawings, in which:

FIGS. 1-7 illustrate a system for flushing a medical device with a pulsating flow of flushing fluid;

FIG. 8 illustrates a fluid delivery device for use in the systems of FIGS. 2, 4, 5 and 6;

FIG. 9 illustrates a cross-sectional view of the fluid delivery device of FIG. 8;

Fig. 10 a-10 d show rear views of the fluid delivery device of fig. 8;

FIG. 11a illustrates an alternative fluid delivery device;

FIG. 11b shows a close-up view of the trigger of the fluid delivery device of FIG. 11 a;

FIGS. 12a and 12b illustrate a gas source for use in the system of FIGS. 1-7;

FIG. 13 illustrates a fluid delivery device for generating a pulsatile flow of irrigation fluid;

FIG. 14 illustrates an exemplary package for supplying components of the irrigation system;

FIG. 15 illustrates a bubble trap;

FIGS. 16 a-c illustrate an alternative bubble trap;

FIGS. 17a through c illustrate another alternative bubble trap;

FIG. 18 illustrates an alternative fluid delivery device for generating a pulsatile flow of flushing gas;

FIG. 19 illustrates a system for irrigating a medical device incorporating a bubble trap device and an alternative fluid delivery device;

FIGS. 20a and 20b illustrate another alternative fluid delivery device for generating a pulsating flow of flushing gas;

fig. 21 illustrates a method for irrigating a medical device, and,

fig. 22 illustrates a method for activating a flushing system.

Detailed Description

The present disclosure relates to systems, devices, and methods for use when flushing medical devices to remove air. Medical devices used in endovascular and percutaneous procedures, such as catheters and stents, are often packaged in sterile environments to mitigate the risk of infection caused by microbial contamination.

However, these medical devices still have to be flushed prior to use in order to remove air and other impurities. An increasing number of people recognize that residual air volumes released during intravascular and percutaneous procedures can cause brain damage. Complete removal of air from medical devices remains a challenge, especially for devices having many channels and slits (such as stents) that can trap small volumes of air, making their removal difficult using conventional irrigation methods.

The inventors have recognized that the efficacy of air removal during flushing can be improved by using a pulsed/pulsating flow of flushing fluid. Pulsed flow enhances the flushing process by disrupting the developing laminar flow and bringing the velocity profile of the flushing fluid closer to that of turbulent or plug flow. The higher degree to which the effect occurs further increases the velocity of the fluid near the surface. Thus, pulse flow increases the effectiveness of flushing in areas where flushing difficulty is greatest.

Fig. 1 illustrates a system 100 for flushing a medical device with a pulsatile flow. The system includes a pulse generator 101 coupled to a purge gas source 102 and a fluid coupler 105. The system also features a syringe pump 103 coupled to the fluid coupler 105 and to the two fluid syringes 104a, 104b via a syringe manifold 107. All components of the system are coupled via a connecting tube 106, which may use any suitable connection, such as a push-fit, interference fit, luer lock, etc.

The pulse generator 101, which is the first fluid delivery device of the system 100, is adapted to provide a pulsating flow of the flushing gas from the flushing gas source 102 to the fluid coupler 105. The fluid coupler 105 is shown as a three-way valve that can be controlled to selectively couple the flush gas or flush fluid from the fluid injectors 104a, 104b to a medical device (not shown). The fluid coupler 105 may alternatively be referred to as a valve manifold, and may take alternative forms (such as a simple three-way connector without a valve). Alternatively, the fluid coupler 105 may have only two connectors or be a connector at one end of a connecting tube.

As will be discussed in more detail later, the pulse generator 101 may be electric or mechanical and arranged to pulse the gas supply from the flushing gas source 102 at regular intervals (e.g. by compressing the connection pipe 106 between the flushing gas source 102 and the fluid coupler 105 at regular intervals, thereby restricting/interrupting the flow of flushing gas).

The syringe pump 103, which is the second fluid delivery device of the system 100, is a user-actuatable pump arranged to aspirate irrigation fluid (in particular irrigation liquid) from the fluid syringes 104a, 104b and to deliver a flow of irrigation fluid to the medical device via the fluid coupler 105. The number of fluid injectors 104a, 104b will depend on the amount of irrigation fluid used to irrigate the medical device. There are two fluid injectors 104a, 104b in the illustrated system 100, but additional or fewer injectors may be used if desired. The syringe manifold 107 has one or more valves positioned to selectively couple each of the fluid syringes 104a, 104b to the syringe pump 103 when desired. It should be appreciated that syringe pump 103 may be any pumping device capable of pumping an uncompressed fluid source from the fluid source to a medical device. Similarly, the fluid coupler 105 and the syringe manifold 107 may be any manifold suitable for selectively coupling a fluid container and a connecting tube, and any suitable connection interface may be used.

The pulsating flow of flushing fluid from the fluid syringes 104a, 104b may be achieved by a user manually actuating the syringe pump 103 at regular intervals, as described in more detail later.

In some examples, the purge gas source 102 may be a tank or the like containing compressed/pressurized carbon dioxide (CO 2). The fluid syringes 104a, 104b can contain a sterile liquid (such as a perfluorocarbon solution or saline) that can optionally be a degassed and/or pH adjusted buffer solution.

An alternative system 200 is shown in fig. 2. The system 200 features the same pulse generator 101 and source 102 of flushing gas, but the syringe pump 103 of the previous system 100 is replaced with a syringe pump 203 in which the fluid syringes 104a, 104b are housed in the syringe pump 203 (i.e., not connected via a connecting tube). The fluid syringes 104a, 104b are preferably removable from the syringe pump 203 to allow replacement and replacement of the fluid sources as necessary. As will be described in more detail later, the syringe pump 203 is preferably characterized by a user-actuatable control for selecting between the fluid syringes 104a, 104 b. The system 200 operates in otherwise the same manner as the previous system 100.

The system 200 of fig. 2 is more compact and requires fewer connection tubes than the system 100 of fig. 1, which also reduces the likelihood of disconnection during the flushing process. However, the syringe pump 103 of the system 100 in fig. 1 is somewhat simpler and potentially cheaper to manufacture than the syringe pump 203 shown in fig. 2.

Another alternative system 300 is shown in fig. 3. The syringe pump 103 and fluid syringes 104a, 104b are identical to the system 100 shown in fig. 1, but the pulse generator has been replaced with a user-actuatable (i.e. manually operated) gas trigger 301. Instead of using an electric or mechanical pulse generator to provide regular pulses, the user squeezes the gas trigger 301 at regular intervals to interrupt the flow of purge gas from the source 102 of purge gas. It should be noted that the gas trigger 301 may also be adapted to provide a flow of gas when the trigger is squeezed (rather than interrupt the flow of gas), and that the pulses may be generated in a similar manner.

While the gas trigger 301 is shown in a preferred configuration (in which it is directly connected to a canister of purge gas), alternatives are contemplated in which sequentially connected triggers (i.e., coupled to the purge gas source 102 via one or more connecting tubes) may be used.

In contrast to the systems 100 and 200 of fig. 1 and 2, the system 300 of fig. 3 does not require an electrical or mechanical pulse generating device and is therefore simpler and cheaper to manufacture. However, it is somewhat more complicated to use, as the operator must manually control each flushing gas pulse.

The system 400 shown in fig. 4 actually combines the syringe pump 203 of fig. 2 with the gas trigger 301 of fig. 3.

In the system of each of fig. 1-4, the flow of flushing fluid from the flushing gas source 102 and the fluid injectors 104a, 104b is actually connected in parallel to the fluid coupler 105. Fig. 5-7 illustrate examples of alternative systems in which the purge gas source 102 and the fluid injectors 104a, 104b are actually connected in series.

In each of fig. 5-7, the three-way valve used as the fluid coupler 105 in fig. 1-4 is replaced with a fluid coupler 505, which is a simple connector, such as a luer lock.

In fig. 5, the components are virtually identical to those in fig. 2, except that the source 102 of flushing gas is coupled to the fluid coupler 505 via the syringe pump 203, and the syringe pump 203 is coupled to the fluid coupler 505 via the pulse generator 101. In this example, pressurized gas from the purge gas source 102 flows through the syringe pump 203 (i.e., the syringe pump 203 is not used to drive the flow of purge gas from the purge gas source 102), and the pulse generator 101 provides a pulsed flow of purge gas (e.g., through the compressed connection tube 106, as previously described).

When the system 500 is used to deliver a pulsatile flow of flush fluid from the fluid injectors 104a, 104b, the flow of flush gas from the flush gas source 102 is stopped (e.g., using a valve on the flush gas source 102), and the injector pump 203 is then used to pump flush fluid from the fluid injectors 104a, 104b, as in the previous embodiments. The pulse generator 101 should be in a passive state at this stage to allow an unobstructed flow of the flushing fluid driven by the syringe pump 203.

The alternative system 600 shown in fig. 6 is basically a hybrid of those shown in fig. 3 and 5, except that the gas trigger 301 of fig. 3 is instead an integral gas trigger 601 integrated into a syringe pump 603. As shown in fig. 3, there is no separate electrical or mechanical pulse generator. It should be noted that the gas trigger 301 of fig. 3 may also be used in the system 600 of fig. 6 instead of the integrated gas trigger 601.

Likewise, the alternative system 700 shown in fig. 7 is basically a mixture of those shown in fig. 1 and 5, with the purge gas source 102 connected to the injector manifold 107. The valves of the injector manifold 107 are used to selectively switch between the fluid injectors 104a, 104b and the purge gas source 102.

Those skilled in the art will appreciate that additional modifications may be made to the systems disclosed in fig. 1-7 by combining different aspects of these systems, and such modifications are contemplated by the inventors. Furthermore, the various components may be integrated together (e.g., the pulse generator may be integrated into a holder for a source of flushing gas).

As previously discussed, the syringe pump 203 utilized in the systems of fig. 2 and 4-6 has user actuatable control means for selecting between the fluid syringes 104a, 104 b. As shown in fig. 8 (which shows a rear view of the syringe pump 203), the user-actuatable control device may take the form of a control knob 801 that can be rotated between different positions to selectively couple the syringes 104a, 104b to the pump itself and to the discharge port 802.

The syringe pump 203 is also characterized by the following: a fluid inlet port 803 for coupling to the purge gas source 102; and a fluid exit port 804 for coupling to the fluid couplers 105, 505.

The syringe pump 203 has a body 805 shaped to house a trigger member 806. In use, a user holds the syringe pump 203 with the body 805 in his palm and generates pulses of flushing fluid from the fluid syringes 104a, 104b by applying an actuation force to press the trigger component 806 into the handle portion 805.

The syringe pump 203 may drive fluid through a positive displacement mechanism, as shown in fig. 9. Each time the pump is actuated, the positive displacement pump delivers a fixed volume of fluid.

When the trigger member 806 is actuated, this causes the compression chamber 901 within the syringe pump 203 to be compressed. Thus, any fluid within the compression chamber 901 will therefore experience a compressive force at the same time. In the case of a substantially incompressible liquid, this action will cause the liquid to be driven through the duckbill valve 903 at the outlet of the compression chamber 901. The duckbill valve 903 allows one-way flow of fluid out of the compression chamber 901, thereby preventing fluid from flowing back into the compression chamber 901 through the outlet when the compression chamber 901 expands.

When the trigger member 806 is released, a resilient biasing means (such as the illustrated spring 904) is used to urge/return the trigger member 806 to its original position. This action expands the compression chamber 901 to its original size, thereby reducing the pressure within the compression chamber 901. This causes a volume of liquid to be drawn into the compression chamber 901 via an umbrella valve 902 located at the inlet of the compression chamber 901-this liquid replaces the liquid that was discharged when the compression chamber 901 was compressed. When the compression chamber 901 is compressed, the umbrella valve 902 prevents liquid in the compression chamber 901 from flowing back through the inlet.

It should be noted that while the positive displacement mechanisms of the syringe pump 203 function more effectively in the case of liquids (because they cannot be compressed too much), the mechanisms can also be used to drive gases to some extent (although the compressibility of the gases reduces effectiveness and means that some of the gases in the compression chamber 901 can be compressed rather than expelled when the compression chamber 901 is compressed).

It should also be noted that duckbill valve 903 and umbrella valve 902 may be replaced with other one-way valves. For example, both valves may be duckbill/umbrella valves, or one or both may be different types of valves capable of allowing fluid flow in one direction and restricting/preventing fluid flow in the opposite direction.

Those skilled in the art will appreciate that other arrangements of positive displacement pumps are possible, and that other pumping mechanisms may also be employed to pump flushing fluid (particularly liquid) from the fluid injectors 104a, 104b to the fluid couplers 105, 505.

It will also be appreciated that if the pressure is sufficient to overcome the umbrella valve 902 and duckbill valve 903, the pressurized fluid will be able to flow through the positive displacement mechanism. In this way, gas from the source of flushing gas 102 may flow relatively unimpeded through the positive displacement mechanism in the system shown in fig. 5-7.

The two types of syringe pumps 103, 203 shown in fig. 1-7 may use the same positive displacement mechanism.

The mechanism of the control knob 801 of the syringe pump 203 is shown in more detail in fig. 10a to 10 d. The control knob 801 works by using an "L-shaped" channel to selectively couple two adjacent fluid paths and close all other fluid paths. Thus, at any time, one (and only one) of the syringes is coupled to the pumping mechanism (i.e., to the fluid conduit through the pump via the positive displacement mechanism) or to the discharge port 802, and the other is closed.

In fig. 10a, the control knob 801 is positioned such that the fluid injector 104b is coupled to the drain port 802. In fig. 10b, the control knob 801 is positioned such that the fluid injector 104a is coupled to the drain port 802. In fig. 10c, the control knob 801 is positioned such that the fluid injector 104a is coupled to the pumping mechanism. In fig. 10d, control knob 801 is positioned such that fluid injector 104b is coupled to a pumping mechanism.

Those skilled in the art will recognize that the selective coupling mechanism described above is only one example, and that alternative valve configurations and devices may be used to achieve the same result of selectively coupling the fluid syringes 104a, 104b to the pump mechanisms and/or the discharge ports 802.

Fig. 11a and 11b show a syringe pump 603 with an integrated gas trigger 601. As can be seen in fig. 11b (which shows the gas trigger 601 in an actuated position), the gas trigger mechanism includes a valve element 1101 biased by a biasing member, such as a spring 1102. When no actuation force is applied to the gas trigger 601, the fluid passage in the valve element 1101 is aligned with the fluid passage through the syringe pump 603. When an actuation force is applied to the gas trigger 601, the valve element 1011 is displaced such that the fluid passage in the valve element 1101 moves out of alignment with the fluid passage through the syringe pump, thereby restricting or preventing fluid flow. Spring 1102 serves to return valve element 1101 and the gas trigger to their original positions. Those skilled in the art will appreciate that the mechanism may be reversed to instead restrict fluid flow when the trigger is not actuated and allow fluid flow when the trigger is actuated.

A similar mechanism may be used for the gas trigger 301 shown in fig. 3 and 4.

Turning to fig. 12a and 12b, two examples of the purge gas source 102 are shown. Fig. 12a shows an arrangement for use in the systems of fig. 1, 2, 5 and 6 (and optionally fig. 7), and fig. 12b shows an arrangement for use in the systems of fig. 3 and 4.

In both figures, the source of flushing gas 102 is a tank of pressurized or compressed gas that is held in an upright position by a bracket 1202. When using certain gases, such as CO2, it is important to keep the tank in an upright position, because otherwise liquid CO2 instead of CO2 gas may be discharged from the tank, which in turn will cause the CO2 to be consumed faster. Although not shown in the figures, preferably the sterile filter component/tray is positioned in sequential connection with the source of flushing gas 102.

In both figures, the flow of purge gas may be controlled by valve 1201.

In fig. 12b, the flushing gas source 102 is provided with a gas trigger 301, which operates using a similar principle as the gas trigger shown in fig. 11b, as described before. Furthermore, because the user may have to hold the flush gas source 102 to actuate the trigger, the canister is provided with a guard element 1204 to reduce heat transfer between the user's hand and the canister (the canister may become extremely cold due to gas expansion occurring within the canister during use).

The pulse generator 101 of some of the previous systems is shown in fig. 13. The pulse generator 101 comprises a compression element 1301 configured to compress a portion of the connection tube 106 held in a groove or channel 1302 of the pulse generator 101. The illustrated compression element 1301 is configured to reciprocate when in use to compress and release the connection tube 106. The pulse generator 101 may be said to be in a closed position when it prevents the flow of the flushing gas and may be said to be in an open position when it allows the flow of the flushing gas.

Alternative compression elements are contemplated in which the compression element is a rotating cam element that compresses and releases the connecting tube 106 as it rotates. The exact nature of the compression element 1301 and the channel 1302 is not necessary for the operation of the pulse generator: it is essential that the pulse generator is operable to restrict the flow of fluid therethrough in some manner at regular time intervals.

The pulse generator 101 features a control switch 1303 for activating the pulse generator 101. In some examples, the pulse generator 101 may feature an electric motor (such as a solenoid motor) coupled to the compression element 1301 to drive the compression element. In other examples, pulser 101 may feature a mechanical/clockwork mechanism that drives compression element 1301 by way of a torsion spring or the like that may be coupled to a rotatable cam. When the pulser 101 uses a clockwork mechanism, the control switch 1303 can be used to wind the clockwork mechanism. An optional second switch (not shown) may also be used to start/stop the clockwork mechanism.

The pulse generator 101 may optionally be supplied in a pre-wound state, for example as part of a kit. Such a kit may additionally contain a packaging element 1401 that acts as a stand for the flushing gas source 102 and the fluid injectors 104a, 104b, as shown in fig. 14.

While the systems shown in fig. 1-7 allow for a reliable and efficient irrigation process, proper activation of these systems is important to ensure that air is removed from the irrigation system before the irrigation system is used to irrigate a medical device. The system described previously may optionally be used in combination with a start-up module adapted to separate and capture bubbles entrained in the flow of flushing liquid. The activation module may also be referred to as a bubble trap.

An exemplary start-up module 1500 is shown in fig. 15 a. The start-up module 1500 is substantially disc-shaped (i.e. shaped like a short cylinder) and features an inlet port 1501 and an outlet port 1502 through which the flushing liquid can enter and leave the start-up module 1500. The illustrated start-up module 1500 also includes a drain port 1503 having a drain cap 1504 for sealing the drain port 1503. The drain port 1503 may be shaped to couple to a syringe, such as a vacuum pressure syringe. The space inside the start-up module 1500 acts as a fluid conduit through which fluid can flow from the inlet port 1501 to the outlet port 1502.

As shown in fig. 15b, the illustrated start module 1500 is formed from a first portion 1505 and a second portion 1506 and further includes a number of baffles 1507 a-c. The baffle 1507a is formed as a curved fin that directs the rinse liquid away from the center of the first portion 1505 in a substantially spiral/helical direction. The shutter 1507b is a disc of this kind: which prevents the flow of flushing liquid from the inlet port 1501 directly through the start-up module to the outlet port 1502 and alters the flow of flushing liquid to flow instead via the baffle 1507 b. The baffle 1507c then serves to redirect the flow of the flushing liquid radially inward toward the outlet port 1502 of the second portion 1506. This flow path is further illustrated in fig. 15 c.

The activation module 1500 may be positioned anywhere in the irrigation system before the medical device and after the syringe pump 103, 203. This ensures that all of the flushing liquid from the fluid injectors 104a, 104b passes through the priming module 1500. The purge gas may also flow through the start-up module 1500 so that it need not be removed when purged with gas, depending on the configuration of the purge system.

Alternative start-up modules 1600 a-c are shown in fig. 16 a-c. Each of these start-up modules 1600 a-c features an inlet port 1501, an outlet port 1502, and a drain port 1503 (which may optionally be provided with a drain cap). Each of the start-up modules 1600 a-c includes an internal baffle 1607 positioned to alter the flow of liquid to separate bubbles from the liquid; the general position of each baffle 1600 is superimposed in fig. 16 a-c. The space above each baffle forms a headspace in which gas may accumulate.

Further, in each start-up module 1600 a-c, the outlet port 1502 is offset from the inlet port 1501 such that flushing liquid cannot flow directly through the start-up module 1600 a-c even without the baffle 1600. The offset nature of the ports increases the tortuous internal geometry formed within the actuation modules 1600 a-c. In a preferred example, outlet port 1502 is positioned such that it is lower than inlet port 1501 when start-up modules 1600 a-c are in use. This helps to ensure that the gas is properly separated and does not flow through the exit port 1502.

It should be appreciated that the inlet port 1501 and the outlet port 1502 in these examples may alternatively be axially aligned with each other, with the baffle 1607 acting as a weir to disrupt the flow of flushing liquid. In this case, the baffle 1607 would preferably be perpendicular to the alignment axis (i.e., the line intersecting the inlet port 1501 and the outlet port 1502). However, in any of the examples, the orientation of the baffle 1607 may be changed, provided that the baffle is used to change the flow of flushing liquid between the inlet port 1501 and the outlet port 1502.

Furthermore, the actuation modules 1600a, 1600b in fig. 16a and 16b are shaped to direct or transport the separated bubbles towards the discharge port. In the example shown, this is achieved by having at least one surface angled toward the drain port 1503. That is, at least one surface (preferably the top surface) of the actuation module 1600a, 1600b is skewed/sloped toward the drain port 1503, wherein the drain port 1503 is positioned at the highest point/vertex of the actuation module 1600a, 1600 b.

The inner edges and/or corners of all the actuation modules are preferably curved to prevent air bubbles from accumulating in these areas. However, the baffles may optionally have angled protrusions (such as angled corners or edges) to help agitate the flow of rinse liquid.

While the start-up modules 1600 a-c in fig. 16 a-c each have only one baffle, it should be understood that additional baffles may be used.

The start modules 1600 a-c may be formed from a single piece of material, such as an elastomeric material (such as silicone), or they may be formed from multiple components that are bonded or fused together.

Fig. 17a to c show another alternative bubble trap 1700. The bubble trap 1700 has the features of the bubble trap shown in fig. 16 a-c described above. The bubble trap 1700 is shown in an orientation in which it is intended to be used (as also shown in fig. 20 a-b).

As shown in fig. 17 a-c, the outlet port 1502 is lower than the inlet port 1501. As described above, this ensures that the bubbles are separated and do not flow through the bubble trap (i.e. the vertically offset ports improve gas separation/trapping).

The bubble trap 1700 is otherwise identical to those of fig. 16 a-c, and all features described with respect to those figures may be equally applicable to the bubble trap 1700 of fig. 17 a-c.

The baffles may also be referred to as deflectors, flow disruptors, agitators, agitating elements, agitating members, or the like, and may be any member that disrupts, agitates, or redirects fluid flow. For example, the baffles may be ribs, separate components, or integrally molded components. The baffle may optionally be formed of an elastomeric material, such as silicone.

The purpose of the baffles is to form a tortuous flow path for the flushing liquid through the priming module, and the baffles of all priming modules disclosed herein are arranged to achieve this purpose. The effect is that the flushing fluid is agitated by the baffles (i.e. laminar flow is disturbed) thereby separating bubbles (such as air) from the flow of flushing liquid.

Fig. 18 shows an exemplary pulser 1801 that also serves as a support for the source of rinse gas 102 (which may be considered as a support for the pulser as well), and fig. 18 shows a rinse system 1900 that incorporates the pulser 1801 and the start module 1500.

Like the pulse generator 101 shown in fig. 13, the pulse generator 1801 shown in fig. 18 features a recess or channel 1302 for receiving the connecting tube 106 and can restrict the flow of flushing gas through the tube by compressing the connecting tube 106. The pulse generator also features a control switch 1803 for activation.

As shown in fig. 19, the priming module 1500 may be directly connected to the fluid coupler 1905 via the connecting tube 106 such that all of the irrigation liquid from the fluid syringes 104a, 104b passes through the priming module 1500 before entering the medical device (which will be attached to the fluid coupler 1905). The illustrated fluid coupler 1905 differs from the fluid coupler in the previous example in that it is a multi-valve flush manifold into which the flush gas source 102 and fluid injectors 104a, 104b are (indirectly) coupled, with valves being used to selectively couple different flow paths to a medical device (not shown).

Fig. 20a to b show another exemplary pulse generator 2001 which is similar to the pulse generator in fig. 18. However, the pulse generator 2001 in fig. 20 is further adapted to receive a pulse stream of flushing liquid via the bubble catch device 1700 of fig. 17, which is received in a recess in the side of the pulse generator 2001. As described above, the bubble trap 1700 is oriented such that the outlet port 1502 of the bubble trap 1700 is lower than the inlet port 1501.

The regulator 2002 is used to control the pressure of the purge gas (e.g., carbon dioxide) to a predetermined pressure (e.g., 2 bar). The flushing gas then flows through the connecting tube 2006, which is looped (not shown) into the body of the pulse generator 2001 and positioned in the groove or channel 1302 of the pulse generator 2001 as described in the previous example.

A flow of pulsed flushing liquid may be coupled to the inlet port 1501 of the bubble trap 1700. The outlet port 1502 of the bubble trap 1700 is coupled to a conduit (not shown) within the pulse generator 2001, and a switch 2004 on the pulse generator 2001 is actuatable to select between coupling a flow of flushing liquid or flushing gas to the outlet 2005 of the pulse generator 2001. Button 1703 can be actuated to activate and deactivate the pulse flow of carbon dioxide.

An exemplary method of using the irrigation system disclosed herein will now be described. It is assumed that all components are connected (including all fluid sources) and that all components have been activated when necessary. It should be understood that this method is intended to be exemplary and should not be construed as limiting. Those of skill in the art will appreciate that the steps described below may be performed in a different order while still achieving the same end result.

The method preferably starts with flushing the medical device with a flushing gas, such as CO 2. The fluid couplers 105, 505, 1905 are controlled to couple the flow of the flushing gas from the flushing gas source 102 to the medical device.

The pulse generators 101, 1801 are then activated to repeatedly restrict and allow flow of the purge gas from the purge gas source 102 at regular intervals. The actuation may involve actuating the control switch 1303, 1803 and/or winding a mechanical spring mechanism of the pulse generator 101, 1801. This step may be omitted when using gas flip-flops 301, 601 instead of pulse generators.

The purge gas source 102 may then be activated to release purge gas into the control line 106, such as by using the valve 1201. If an automatic pulse generator 101, 1801 is used, the flush gas source 102 may be activated for a duration sufficient to flush the medical device with flush gas (e.g., CO 2), and the pulse generator 101, 1801 will automatically (i.e., without further user/operator intervention) pulse the flow of flush gas received at the medical device.

If manual gas triggers 301, 601 are used, the operator may actuate the gas triggers 301, 601 at regular intervals to generate a pulsating flow of flushing gas (as opposed to using an automatic pulse generator 101, 1801).

The purpose of flushing with flushing gas is to remove as much air as possible before flushing with flushing liquid, where CO2 is used to displace air and replace it with CO2 (if released into the body it is less harmful than air because it can be more easily dissolved in the blood stream). As described previously, the use of pulsed flow of the flushing fluid disrupts laminar flow and increases the efficacy of air displacement.

Once the medical device has been sufficiently flushed with flush gas, the operator may deactivate the source of flush gas (e.g., by using valve 1201) and may control the fluid couplers 105, 505, 1905 to decouple the flush gas source 102 from the medical device and instead couple the syringe pumps 103, 203, 603 to the medical device.

The syringe manifold 107 or control knob 801 may be used to select between the fluid syringes 104a, 104b (and optionally couple them to a discharge port 802 or the like for actuation prior to flushing the medical device). The trigger component 806 of the syringe pump 103, 203, 603 may then be fully actuated at regular intervals to generate fixed volume pulses of flush fluid from the coupled fluid syringe 104a, 104 b. As mentioned previously, although the fluid injectors 103, 203, 603 are capable of delivering pulses of both gas and liquid (the precursor being any purge gas in the injectors 104a, 104b in an uncompressed/unpressurized state), the fluid injectors 104a, 104b preferably contain a purge liquid rather than a purge gas. A pulse of irrigation fluid may then be delivered as necessary to adequately irrigate the medical device, wherein the pulse is generated each time the trigger member 806 is actuated. The process may then be repeated with flush fluid from the other fluid injector 104a, 104b if desired, and additional fluid injectors may also be used.

Fig. 21 illustrates a flushing method that may be performed using the previously described system.

At step 2101, a lumen of a medical device is irrigated with a pulsed supply of irrigation fluid. The lumen may optionally contain additional medical devices (such as stents) that are also to be irrigated. The method may additionally involve coupling the lumen to a pulsed supply of irrigation fluid.

The flushing fluid may be a flushing gas (such as carbon dioxide) or a flushing liquid (such as perfluorocarbon or saline solution), which may optionally be a degassed and/or pH adjusted buffer solution. The degassed solution may absorb a substantial amount of the gas (such as carbon dioxide or air) in contact therewith, thereby enhancing gas removal from the medical device.

The method may involve: a first rinsing step with pulsed supply of rinsing gas, and a subsequent rinsing step with pulsed supply of rinsing fluid. In this way, gas can be used to displace air from the medical device, and irrigation liquid can be used to displace and/or absorb irrigation gas and residual air, such as air pockets trapped in the medical device.

In some examples, the method may involve flushing the lumen at a pressure above 101.325kPa (which is a standard pressure). Flushing at higher pressures increases the ability of the flushing fluid to absorb air.

The activation modules 1500, 1600 a-c may be used to assist in removing air from the irrigation system prior to irrigation of the medical device. In an exemplary method, a fluid (such as a saline solution) may be pumped through components of the system via the start-up modules 1500, 1600 a-c, with the drain port 1503 open to allow air to escape. Additionally or alternatively, a negative pressure source (e.g., a vacuum pressure syringe, such asA syringe) may be connected to the drain port 1503 and used to aspirate irrigation fluid through components of the system.

Fig. 22 illustrates such a method for activating a catheter flushing system (e.g., one of the systems in fig. 1-7 or 19).

At step 2201, a source of rinse liquid is coupled to an inlet port of a bubble trap device (e.g., one of the start-up modules shown in fig. 15 and 16).

At step 2202, an air vent or vent port of the bubble trap is opened.

At step 2203, a flow of irrigation liquid is driven through the bubble trap and out the drain port.

At step 2204, the drain port is closed.

The flow of the flushing liquid may be driven by a pump coupled to a source of the flushing liquid, or it may alternatively be driven by a vacuum source (such as a vacuum pressure syringe) coupled to the discharge port.

In all of the above examples, any suitable pulse frequency may be used. Particularly effective frequencies include pulse frequencies between five times per second and once per 10 seconds (inclusive) (0.1 Hz to 5 Hz), preferably between two times per second and once per five seconds (inclusive) (0.2 Hz to 2 Hz), even more preferably between two times per second and once per two seconds (inclusive) (0.5 Hz to 2 Hz). Different pulse frequencies may optionally be used for different flushing fluids (e.g., different frequencies may be used when flushing with gas than when flushing with liquid).

As previously explained, the various components in the above-described systems and devices may be combined and/or interchanged, and the above examples are not intended to be limiting. Similarly, the order of the above-described method steps is intended to be exemplary, not limiting, unless otherwise specified, and it will be understood by those of skill in the art that the order of certain method steps may be altered without affecting the end result.

Although the above-described start-up module is preferably used in conjunction with one of the above-described systems, it is also suitable for use with other flushing systems, such as those that use only flushing liquid (i.e., do not use flushing gas).

Also, while the pulse flushing method disclosed herein is preferably used in conjunction with one of the systems described above, it may alternatively be used with any other suitable flushing system.

Furthermore, while the method is preferably used to flush the lumen of a medical device (such as a catheter), the systems and methods disclosed herein may be used to flush any suitable medical device, particularly when placed within the lumen. For example, a similar stent graft may be irrigated while within the lumen of a catheter. The method may also be used to flush medical devices placed in other containers (i.e., they are not only suitable for flushing lumens of medical devices and medical devices placed therein).

Claims (50)

1. A system for flushing a lumen of a medical device to remove air, the system comprising:

a first fluid delivery device adapted to provide a pulsatile flow of a flushing gas from a pressurized source of the flushing gas;

a second fluid delivery device adapted to provide a pulsatile flow of the flushing liquid from a source of the flushing liquid; the method comprises the steps of,

at least one fluid coupler for connecting the first and second fluid delivery devices to the lumen of the medical device.

2. The system of claim 1, wherein the first fluid delivery device comprises a flow restrictor actuatable between an open position and a closed position to pulse the flow of flush gas.

3. The system of claim 1 or claim 2, wherein the first fluid delivery device comprises a compression element configured to compress a flexible tube coupled to the source of the flushing gas at predetermined time intervals, thereby restricting a flow of the flushing gas through the tube.

4. A system according to claim 3, wherein the compression element is reciprocally movable.

5. The system of claim 4, wherein the compression element comprises a solenoid motor.

6. A system according to claim 3, wherein the compression element comprises a rotatable cam.

7. The system of claim 6, wherein the rotatable cam is coupled to a torsion spring adapted to drive the rotatable cam.

8. The system of any of claims 3, 4, or 6, wherein the compression element is coupled to an electric motor configured to drive the compression element.

9. A system according to any one of claims 3, 4 or 6, wherein the compression element is pneumatically drivable, preferably wherein the compression element is pneumatically drivable by the flushing gas.

10. The system of claim 1 or claim 2, wherein the first fluid delivery device comprises a user-actuatable gas control mechanism for providing the pulsating flow of the flushing gas.

11. The system of any preceding claim, further comprising a stand adapted to hold the source of flushing gas in an upright position, preferably wherein the stand comprises the first fluid delivery device.

12. The system of any preceding claim, wherein the second fluid delivery device comprises a user-actuatable liquid delivery mechanism for providing the pulsatile flow of the flushing liquid, preferably wherein the user-actuatable liquid delivery mechanism is a trigger.

13. The system of claim 12, wherein the second fluid delivery device comprises a user-actuatable positive displacement pump.

14. The system of claim 13, wherein the positive displacement pump comprises a compression chamber.

15. The system of claim 14, wherein a positive displacement pump comprises a one-way valve configured to allow one-way flow of flushing liquid from the source of flushing liquid into the compression chamber.

16. The system of any of claims 13-15, wherein the positive displacement pump comprises a one-way valve configured to allow one-way flow of flushing liquid from the positive displacement pump toward the at least one fluid coupler.

17. The system of any of claims 13-16, wherein the positive displacement pump comprises one or more resilient compression members arranged to: resetting the user-actuatable liquid delivery mechanism to an initial position and/or aspirating the irrigation liquid from the source of irrigation liquid.

18. The system of any preceding claim, wherein the fluid coupler is a three-way valve.

19. The system of any preceding claim, wherein the first fluid delivery device and the second fluid delivery device are included in a single device.

20. The system of any one of claims 1 to 18, wherein the first fluid delivery device is coupleable to the fluid coupler via the second fluid delivery device.

21. The system of any preceding claim, wherein the flushing liquid is a first flushing liquid, and wherein the second fluid delivery device is further adapted to provide a pulsating flow of the second flushing liquid from a source of second flushing liquid, preferably wherein the second fluid delivery device comprises a control device for selectively coupling the second fluid delivery device to the respective sources of first flushing liquid and second flushing liquid.

22. The system of any preceding claim, further comprising a sterile filter positionable in sequential connection between the first fluid delivery device and the pressurized source of the flushing gas.

23. A method for flushing a lumen of a medical device to remove air prior to introducing the medical device into a body, the method comprising:

the lumen is flushed with a pulsed supply of flushing fluid.

24. The method of claim 23, wherein the flushing fluid is a flushing gas.

25. The method of claim 24, wherein the method further comprises flushing the lumen with a pulsed supply of flushing liquid.

26. The method of claim 24 or 25, wherein the purge gas is carbon dioxide.

27. The method of claim 23, wherein the flushing fluid is a flushing liquid.

28. The method of any one of claims 25 to 27, wherein the rinsing liquid is a buffer solution.

29. The method of any one of claims 25 to 28, wherein the rinse liquid is pH adjusted.

30. The method of any one of claims 25 to 29, wherein the flushing liquid comprises saline.

31. The method of any one of claims 25 to 30, wherein the rinse liquid is degassed.

32. The method of any one of claims 25 to 27, wherein the rinse liquid is a perfluorocarbon solution.

33. The method of any one of claims 23-32, wherein flushing the lumen comprises flushing at a pressure above 101.325 kPa.

34. The method of any one of claims 23-33, wherein flushing the lumen comprises coupling the lumen to the pulsed supply of flushing fluid.

35. A bubble trap for trapping bubbles entrained in a flow of liquid, the bubble trap comprising:

A discharge port for discharging bubbles from the bubble catching means;

an inlet port for receiving the flow of the liquid;

an outlet port; the method comprises the steps of,

a fluid conduit coupling the inlet port to the outlet port,

wherein the fluid conduit comprises at least one baffle arranged to alter the flow of the liquid through the fluid coupler, thereby separating bubbles from the flow of the liquid.

36. The bubble trap device of claim 35, wherein the bubble trap device is shaped to direct separated bubbles toward the discharge port.

37. A bubble trap according to claim 35 or claim 36, wherein the at least one baffle is formed of an elastomeric material, preferably wherein the at least one baffle is formed of silicone.

38. A bubble trap according to claim 35 or 36, wherein the at least one baffle is formed of a rigid material, preferably wherein the at least one baffle is formed of polycarbonate.

39. A bubble trap according to any one of claims 35 to 38, wherein the at least one baffle is arranged to interrupt laminar flow of the liquid within the conduit.

40. The bubble trap of any one of claims 35 to 39, wherein the at least one baffle comprises one or more angled projections.

41. The bubble trap of any one of claims 35 to 40, wherein the inlet port and the outlet port are arranged on opposite sides of the bubble trap, and wherein the at least one baffle is positioned between the inlet port and the outlet port and arranged perpendicular to a line intersecting the inlet port and the outlet port.

42. The bubble trap of any one of claims 35 to 41, preferably wherein the discharge port is sealable, wherein the discharge port is shaped to be coupled to a syringe.

43. The bubble trap of any one of claims 35 to 42, wherein the housing of the bubble trap is formed of an elastomeric material, preferably wherein the elastomeric material is silicone.

44. The bubble trap of any one of claims 35 to 42, wherein the housing of the bubble trap is formed of a rigid material, preferably wherein the rigid material is polycarbonate.

45. A catheter flushing system, comprising:

A source of rinsing liquid;

a pump for driving the flushing liquid; the method comprises the steps of,

the bubble trap device of any one of claims 35 to 42,

wherein the inlet port of the bubble trap device may be coupled to the source of flushing liquid.

46. The catheter flushing system of claim 45, wherein the pump is coupleable to the inlet port of the bubble trap.

47. The catheter flushing system of claim 45, wherein the pump is coupleable to the discharge port of the bubble trap.

48. A method of activating a catheter flushing system, the method comprising:

coupling a source of rinsing liquid to an input port of the bubble trap device;

opening a vent on the bubble trap;

driving a flow of the flushing liquid through the bubble trap means and out a discharge port; the method comprises the steps of,

closing the discharge port.

49. The method of claim 48, wherein the flow of the rinse liquid is driven by a pump coupled to the source of the rinse liquid.

50. The method of claim 48, wherein the flow of rinse fluid is driven by a vacuum source coupled to the discharge port of the bubble trap device.