WO2009021170A1

WO2009021170A1 - L-tube having vent filter

Info

Publication number: WO2009021170A1
Application number: PCT/US2008/072588
Authority: WO
Inventors: John Muri; Gaylene Fisch; Bryan Knodel
Original assignee: Medco International, Llc
Priority date: 2007-08-09
Filing date: 2008-08-08
Publication date: 2009-02-12

Abstract

A method and apparatus for venting air from a device that does not allow fluid to escape the device. In a catheter system, all the interior volumes around the catheter needle, catheter, catheter housing as well as all internal volumes in fluid communication with the catheter needle will be vented through a filter plug as Flashback occurs. A hydrophobic filter can be used as the filter plug. A valve can be attached to device via to allow luer connecting to the device. Placement of the filter in close proximity to the valve and specific orientation of the device configuration results in substantially all air near the valve being evacuated during flashback. A clinician then has direct access to this blood filled volume to take blood out, or provide access to medicate the patient.

Description

L-TUBE HAVING VENT FILTER

BACKGROUND OF THE INVENTION

Field of the Invention The present invention pertains to canulation using catheters and, more particularly, to venting during canulation allowing for flashback that insures proper percutaneous placement of a catheter.

Description of the Prior Art

Catheters are used to provide fluid communication with patients. A catheter can allow for the introduction of fluids into a patient and removal blood from a patient. Of the many types of catheters currently existing, a popular catheter that is relatively common is an over the needle type arrangement, wherein the needle and catheter are provided in a coaxial arrangement. The needle is used to provide a point of entry for the catheter into a patient by inserting the needle into the patient's vein and sliding the catheter over the needle into the vein of the patient while removing the needle from the vein of the patient. Prior to percutaneous insertion of the needle into the patient, the inner lumens of the needle and its connections are typically filled with air. During catheter placement, the catheter needle punctures the vein of the patient causing blood to rush into these lumens as a result of venous pressure. The blood rushes through the lumen within the needle and those lumens for components that are in fluid communication with the needle.

A desirable feature within catheters and catheter components is the ability to visualize the blood within at least one of these fluidly connected components as quickly as possible. This visualization of blood after percutaneous insertion of the needle into the patient is generally referred to as Flashback. It is, therefore, desirable to configure components in fluid communication with the catheter needle in a manner that will allow a clinician to visualize the Flashback and confirm correct vena-puncture.

The venous pressure causes blood to rush through the lumens of the needle and those components in fluid communication with the needle lumen forcing the air contained within these lumens to be pushed out. This air needs to be suitably vented without allowing the blood to escape. Currently available systems do not allow for this venting in a satisfactory manner.

Catheter systems need to provide adequate venting of the interior lumens during introduction of the needle into the vein of the patient in order to comply with certain FDA and ISO requirements and be usable as an IV catheter. Currently available systems do not provide venting that is realizable or compliant with FDA and ISO requirements in a satisfactory manner.

In view of the foregoing discussion, it is readily apparent that there remains a need in the relevant art for a catheter system that provides adequate venting to allow for the necessary flashback.

SUMMARY OF THE INVENTION

The embodiments of the invention discussed herein address the above discussed shortcomings in the prior art.

An embodiment has an objective to provide for adequate venting of the catheter during introduction of the catheter needle into the vein to insure proper catheter placement.

An object of another embodiment is to provide visualization of flashback at that moment venous pressure causes blood to rush up the lumen of the needle and lumens that are in fluid communication with the needle lumen.

An object of another embodiment is to configure components of a catheter system so that they are in fluid communication with at least one of the components being vented to allow for flashback and visualization of the flashback to confirm correct vena-puncture.

An object of another embodiment is to allow for an escape path for air that exists within inner lumens of the needle and components in fluid communication with the needle lumen before the percutaneous insertion of the needle into the vein of a patient.

An object of another embodiment is to provide a catheter with components with a suitable vent system with provisions for air to be pushed out as blood rushes in upon canulation such that the vent system does not allow blood to escape. An object of another embodiment is to provide a hydrophobic filter plug within a vent for a catheter component to yield suitable flashback functionality.

An object of another embodiment is a hydrophobic filter plug within a vent for a catheter component to allow air through but be closed to fluids.

An object of another embodiment is a hydrophobic filter plug within a vent for a catheter component to allow air through but be closed to fluids, the filter once touched by fluid resulting in a seal for air.

An object of another embodiment is to provide a method for placing a hydrophobic filter plug within a vent for a catheter component to initially allow air flow but be closed to the flow of fluids such that once the interior portion of the hydrophobic filter is saturated with fluid, those interior cells of the hydrophobic filter will retain fluid if the pressure of the fluid inside the catheter component subsides preventing air from being pulled in from outside the filter. An object of another embodiment is to provide an assembly that allows a clinician to access to a blood filled volume within a component for a catheter system to remove blood out, or provide access to medicate the patient.

An object of another embodiment is to provide needle-less access to an interior, vented volume of a catheter assembly. An object of another embodiment is to provide needle-less access to a valve that can be opened by a luer connection, and automatically closed when the luer is disconnected.

An object of another embodiment is to provide a hydrophobic filter plug placed within a component for a catheter assembly to minimize the interior volume of the component.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross sectional diagram of a catheter system; FIG. 2 is a perspective view of a catheter system; FIG. 3 is a cutaway view of the catheter system 10 of FIG. 2; FIG. 4 is a perspective view of a catheter system 10; FIG. 5 is a perspective view of a catheter system 10;

FIG. 6 is an exploded view of a catheter system.

DETAILED DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a catheter system, generally referred to as 10, having a catheter 12, catheter needle 14 catheter housing 16, safety tube with needle retraction device 18, L-tube 20 with internal volume 25 and needle-less valve 23.

The catheter 14 and needle 16 are formed as what is commonly known as an over the needle bloodless system. The catheter 12 is mounted to catheter housing 16 and the catheter needle 14 is in sliding engagement with the catheter housing 16 such that the needle can be retracted into safety tube 19 upon activation of needle retraction device 18. Seal 15 provides isolation between the internal area defined by safety tube 19 and catheter housing 16. Seal 15 can be made from an elastomeric material that allows needle 14 to move through an aperture with seal 15 while maintaining sealing engagement with the needle 14.

An embodiment employs L-tube 20 as a catheter component attached to catheter housing 16 at L-tube port 17. The L-tube 20 can be held in a sealing engagement with catheter housing 16 using o-ring 27 at the junction between L-tube port 20 and catheter housing 16. The sealing engagement between catheter housing 16 and L-tube port 17 can be an arrangement that is fixedly secured by compatible attachment mechanisms and still remain moveable. An embodiment could have a male attachment mechanism 31 formed at L-tube port 17 that is compatible with a female attachment mechanisms 32 formed on L-tube 20. It should be noted that there are many attachment mechanisms that can be used to attach L-tube 20 to L-tube portl7 that will be readily apparent to those skilled within the art of catheters. L-tube 20 has an internal volume 25 that is in fluid communication with the lumens defined by needle 14, catheter housing 16 and L-tube port 17.

In an embodiment, needle-less valve 23 is connected to L-tube 20 using a luer connection. A male luer fitting 36 can be formed on needle-less valve 23 that mates with a female luer connector 26 on the L-tube 20. Once the luer connection is made, an interior lumen defined by needle-less value 23 is in fluid communication with the internal volume 25 of L-tube 20. Upon removal of the luer connection, the female luer connector 26 closes, thus sealing the internal volume 25 of the L-tube 20. L-tube 20 has a vent 21 formed therein with a filter 22 placed inside the vent. The function of the vent 20 is to allow air to escape from the internal volume 25 of L-tube 20 and the lumens defined by needle 14 and catheter 12. Design choices for materials used for L-tube 20 can include transparent or translucent materials commonly used with the art of catheters. It is also envisioned that employing a color coded L-tube 20 that identifies that gauge of the luer connection that is to be used with L-tube 20.

Flashback can be controlled by placement of a venting mechanism within a component that is to be used in conjunction with the catheter 12. The placement of vent 21 in an area separate from the catheter housing 16 provides an area that can be arranged independently from the positioning of catheter housing 16 and therefore, specifically arranged for observing and controlling Flashback. The venting is controlled by having a vent 21 contained within the L-tube 20 allowing the air with the lumen defined by needle 14 and those lumens within fluidly connected components to vent air from the catheter assembly. Once Flashback occurs, the blood pressure from the vena-puncture will force air through the vent 21 until blood reaches the filter plug 22. The filter plug 22 can be formed from a hydrophobic or other material that will allow air to pass but not fluid. The Flashback is controlled using the filter 22 within vent 21 to allow air contained within the various fluidly connected lumens to escape until blood reaches filter 22 resulting in the stoppage of flow through vent 21. Thus, air originally contained within the lumens defined by needle 14, catheter housing 12 and the internal volume of L-Tube 20 passes through vent 21. Proper positioning of vent 21 during canulation will allow the all the air within the lumens defined by needle 14, catheter housing 12 and the internal volume of L-Tube 20 to escape. Once the air has vent out, the blood from the Flashback will be forced upon the interior region of the filter 22 and stop venting through vent 21.

An unexpected advantage that results from the placement of a vent in a component other that the catheter housing 16 itself is the capability of providing a second port 26 different from the L-Tube port 17 that can also have air completely evacuated from the internal volume 25 of the L-Tube 20 near the second port 26. As shown in FIG. 1, the second port could be a luer connector with the vent 21 located in the vicinity of the luer connector. After Flashback, the air that formerly existed near the area of the second port 26 is evacuated, thus allowing for connection of another component to either withdraw blood from the canulated patient or to administer fluids. Placement of the vent in area adjacent to the second port, abutting the second port or placed such that the interior areas of the second port and the vent are contiguous will provide for the removal of air from the area inside the second port. Therefore, a needle-less valve 23 can be connected to the second port, immediately, to begin the delivery of fluids and/or medication or to withdraw blood from the canulated patient.

FIG. 1 illustrates a needle-less valve 23 that is connected to second port 26. As shown in FIG. 2, the second port 26 is constructed to function as a female luer connector. The needle-less value 23 has a compatible male luer 36 connector to connect to the female luer connector configuration of second port 26. Placement of the vent 21 near or adjacent the second port 26 allows virtually all the air contained in the interior spaces defined by the lumens defined by needle, 14, catheter 12, catheter housing 16 and internal volume 25 (which includes the volume near the second port 26) to be evacuated upon Flashback. Examples of sources for needle-less valves are Alaris^®; Cardinal Health^®; Rymed Technologies, Inc.;

Creative Plastic Technology, LLC; ICU Medical, Inc.; B. Braun Melsungen AG; and various others that will be readily apparent to those skilled in the art. An important function of catheters as well as valves and other components used within catheter assemblies, is the necessity for complying with requirements of the Food and Drug Administration (FDA) and International Organization for Standardization (ISO). The FDA and the ISO require that to be a usable IV catheter within the field, the provision for adequate venting of the catheter during introduction to the vein must be provided. During the catheter placement the needle punctures the vein, and at that moment venous pressure causes blood to rush up the interior volumes of the needle and its fluidly connected components. At least some of the fluidly connected components are configured to allow the clinician to visualize the presence of blood, or the so called Flashback, to confirm correct vena-puncture. Prior the vena-puncture of a patient, interior volumes (the inner lumen of the needle, catheter, catheter housing and fluidly connected components are filled with air. Upon vena- puncture blood rushes into the interior volumes and this internally contained air needs to be vented so that it can escape from these interior volumes. Therefore, a suitable vent system is needed to allow the air to vent out while keeping the blood inside. A hydrophobic filter plug is suitable to such function. For example, hydrophobic filters that can function as filter 22 are those available from Poreχ^E . The hydrophobic filter functions to let air through but not fluids. Another function of the filter is to form a complete seal once exposed to fluid. In the case of Flashback, the blood rushes into the interior volumes and air is vented through filter 22 until the blood touches the filter 22, at which point the filter 22 forms a complete seal to fluid as well as air; this happens at the interface of the filter 22 wherein the interior volume of the L-Tube 20 meets the inside of the filter 22. At this interface, the blood will meet the filter 22 and the blood fluid saturates the cells of the filter 22 that come into contact with the blood fluid. These cells retain that fluid in those cells, thus, if the pressure of the blood fluid in the interior volumes subside no air is pulled in from outside the filter. The assembly shown in FIG. 1 additionally provides features that allow access to the internal blood filled volume after canulation of the patient to either remove blood or to provide needle-less access to medicate the patient. An assembly such as that shown in FIG. 1 allows a needle-less valve to be connected to second port 26 immediately after canulation of the patient because all the air within the interior lumens has been removed. Thus, access to this blood filled volume is provided quickly and easily. Second port 26 is shown as a valve opening having a male luer connection pushed inside the valve (second port 26) that automatically closes once male luer connection is removed. The hydrophobic plug or other material used as filter 22 can be placed close to second port 26 to substantially eliminate or minimize any air from the interior lumens of the catheter assembly in the vicinity of second port 26 during Flashback.

FIG. 1 illustrates a cross section of system 10 having a catheter 12, and needle 18 contained within a catheter housing 16 having an L-tube 20 attached at L-Tube port 17. The L-Tube 20 has vent 21 contained a filter 22. A needle-less valve 23 is luer connected to the L-Tube 20 near valve 23. As shown in FIG. 1, filter 22 is in close proximity to valve 23, minimizing the non-vented volume of air that results after Flashback. All the interior volumes around the needle 18, the catheter 12, and catheter housing 16 the internal volume 25 within L-Tube 20 is vented through the filter plug as Flashback occurs in a single direction form interior to exterior and in a single direction by using a filter 22 that can perform this function, such as a hydrophobic filter. An embodiment provides that the interior volumes for catheter 12, needle 18, catheter housing 16, L-tube 20, L-tube port 17, vent 21, filter 22 and second port 26 are formed to be flush with each other. Forming flush interior surfaces prevents air and fluids from being trapped within the internal volumes to the catheter assembly. Flush surfaces also enhance the flow of air and blood during Flashback. The removal of blood or the administration of fluid medication is enhanced by having flush surfaces internal to the catheter system. It should be understood that flush as used herein refers to surfaces that are flush within manufacturing tolerances for the various components. Therefore, flush as used herein refers to substantially flush. FIG. 2 is a perspective view of a catheter system 10 having a catheter 12 and needle

18 attached to a catheter housing 2. An L-tube 20 is attached housing 2 at L-Tube port 17. The L-Tube 20 is configured with a vent 21 and a filter 22. A needle-less valve 23 is luer connected to the L-Tube 20 near vent 21. Filter 22 can be placed close to valve 23 to minimize any non-vented volume of air after Flashback. The interior volumes around the needle 14, the catheter 12, and catheter housing 16 the internal volume 25 within L-Tube 20 are vented through the filter 22 during Flashback in a single direction using a filter that can perform this function, such as a hydrophobic filter. As shown in FIG. 2, the vent 21 is configured to vent in a vertical direction with filter 22 being exposed to the ambient surroundings at the top of vent 21. Cap 14 is removed exposing needle 18 (not shown) allowing vena penetration of a patient. Canulation is completed by extending forward flange 22. Finger grips 41 are provided on top and bottom of safety tube 16 to allow convenient and advantageous mechanism for the clinician to hold the system 10 while vena penetration and canulation are being performed. Once the patient has been canulated, actuating device 38 retracts needle 18 (not shown) into safety tube 16. A biasing mechanism (not shown) is secured by securing device 56 inside safety tube 16.

FIG. 3 is a cutaway view of FIG. 2 along the line A-A' of catheter system 10 showing catheter 12 and needle 18 attached to a catheter housing 2 inside of cap 14. The interior lumens of L-tube 20, housing 2 and needle 18 are illustrated in FIG. 3 as being a continuous volume that are in fluid communication with one another. Vent 21 and filter 22 are placed close to luer port 26 and positioned to maximize the volume of air that is vented during Flashback. The interior volumes around the needle 18, the catheter 12, catheter housing 16 and the internal volume 25 within L-Tube 20 are vented through the filter 22 during Flashback allowing blood to fill these entire volumes. Cap 14 provides protection for needle 18 and catheter 12 from ambient surroundings during transportation of the system 10 and prevents accidental sticking by needle 18. Canulation is completed by extending forward flange 22. Finger grips 41 are located on the top and bottom of safety tube 16 rather than the sides to provide a convenient and advantageous mechanism for the clinician to hold the system 10 while vena penetration and canulation are being performed. Once the patient has been canulated, actuating device 38 allows the clinician to retract needle 18 into safety tube 16. Biasing mechanism 26 is secured by securing device 56 inside safety tube 16. The needle 18 extends through seal 44 and is attached to biasing mechanism 26 with seal 44 isolating the interior volumes defined by L-tube 20, housing 2 and needle 18 from the inside of safety tube 16. Once needle 18 is retraced into safety tube 16, the seal 44 self seals itself to isolate the interior volumes defined by L-tube 20, housing 2 and needle 18 from the inside of safety tube 16.

Figures 4 and 5 are perspective views of a catheter system 10. Figures 4 and 5 have vent 21 arranged to point in a horizontal direction. FIG. 4 shows vent 21 arranged such that it is offset by 180° with respect to luer port 26. FIG. 5 shows vent 21 arranged such that it is offset by 90° with respect to luer port 26. The remaining portions of Figures and 4 and 5 are the same as illustrated in FIG. 2; therefore, the description of FIG. 2 is referred to for that portion.

FIG. 6 is an exploded view of catheter system 10 with needleless valve 23 that attaches to L-tube 20. Filter 21 is of a size and shape to accommodate filter 22 such that a seal is formed that allows air to pass but not fluid. In one particular embodiment, once filter 22 is touched by fluid, air can no longer pass through filter 22. L-tube 20 attaches to housing 6 with an o-ring 66 used to form a seal at the junction between the L-tube 20 housing 6 such that it does not interfere with air or fluid flow. This can be accomplished by retaining a substantially flush surface at the junction between L-tube 20 and housing 6 after o-ring 66 is in place. The distal end of housing 6 forms areas for attaching flange 22 and catheter 12. Needle 18 is attached to biasing device 26 either by crimping or other means. Biasing device 26 is attached to the proximal end of safety tube 16 with rod 56 and seal 44. Needle 18 is then extended through seal 44 and through catheter 12 and locked in place until released by actuating mechanism 38. Once vena puncture is achieved, the air inside the interior lumens formed by catheter 12, needle 18, housing 6 and L-tube 20 is forced through filter 22. The blood will reach filter 22 after venting has completed, thus stopping the venting operation and providing control of the Flashback through venting. After canulation is performed, actuating device 38 can be depressed to retract needle 18 into safety tube 16. Seal 44 maintains the seal between the interior of the safety tube 16 and relative integrity of the interior lumens formed by catheter 12, needle 18, housing 6 and L-tube 20.

Claims

IN THE CLAIMS

1. A venting system comprising: a component having a body with at least one port and a first attachment mechanism associated with the port; a vent formed in the component module; and a filter within the vent having an initial state in which air can pass through the filter but fluid can not pass through the filter and a secondary state achieved once the filter is exposed to fluid in which the filter will no longer allow air to pass.

2. The system of claim 1 further comprising: a device having a second attachment mechanism formed on the device that is compatible with the first attachment mechanism to form a sealing engagement once connected at a junction between the component module and the device, the sealing engagement not allowing fluid or air to escape through the junction between that component module and the device;

3. The system of claim 2 wherein the sealing engagement further comprises a seal ring between the first attachment mechanism on the component module and the second attachment mechanism on the device.

4. The system of claim 2 wherein the junction is rotatable while maintaining the sealing engagement.

5. The system claim 2, wherein the component module and the device are initially filled with air and upon introduction of fluid into the device air is evacuated from all areas in fluid communication with the device.

6. The system of claim 2 further comprising a second port located near the vent, wherein the second port can be selectively opened or closed, such that introduction of fluid into the device evacuates the device and an adjacent volume of air within the component module at least near the second port.

7. The system of claim 1, wherein the component module is color coded for a size of a connecting device used to connect to the second port.

8. The system of claim 2 wherein the device, the component module, the vent and the filter have interior surfaces configured to be substantially flush with each other.

9. The system of claim 2 where the device is a catheter device having a catheter needle arranged on an end of the device.

10. A venting system comprising: a tube assembly having a first port with a first attachment mechanism formed near the first port; a device having a second attachment mechanism that can be fixedly attached to the first attachment mechanism of the tube assembly to formed a junction between the tube assembly and the device at the first port that is a sealing engagement not allowing fluid or air to escape through the junction between the tube assembly and the device; a second port formed on the tube assembly and in fluid communication with the device, the second port capable of being selectively placed into an opened or a closed position, and a vent formed in the tube assembly, the vent having with a filter that has an initial state allowing air to pass through the filter while preventing fluids from passing through the filter, and a secondary state that is reached once the filter is exposed to fluid in which secondary state the filter will no longer allow air to pass, such that introduction of fluid into the device evacuates air from the device and any devices in fluid communication with the device.

11. The venting system of claim 10 wherein the vent is located near the second port such that while the second port is in the closed position a volume of air within the tube near the second port is evacuated through the filter upon introduction of fluid into the device until fluid reaches the filter.

12. The venting system of claim 11 , wherein the second port is a needle-less port that is accessed through luer connection and the device is a catheter device having a hollow portion with a catheter needle attached.

13. The venting system of claim 12, wherein the tube assembly is color coded relative to gauge of luer connection required for the needle-less port.

14. The venting system of claim 10, wherein the tube, the vent and the filter have interior surfaces configured to be substantially flush with each other forming an interior volume that enhances both air flow and fluid flow.

15. A method of venting a catheter system during flashback comprising the steps of: providing a module having at least a partly hollow interior with a first port having a first attachment mechanism that is attached to a device having a hollow portion, the device having a second attachment mechanism that mates with the first attachment mechanism such that the device attaches to the first port in a movable, sealing engagement with the hollow portion in fluid communication and with the partly hollow interior; placing a vent in the module with a filter in the vent, the filter allowing air to pass but not allowing fluid to pass until the filter is exposed to fluid at which time the filter will no longer allow air to pass; forming a second port within the module that can be selectively opened or closed; and evacuating air from the hollow interior and the hollow portion by introducing a fluid substance into the device.

16. The method of claim 15 wherein the step of forming further comprises locating the second port near the vent.

17. The method of claim 16 wherein the step of evacuating further comprises evacuating a volume of air within the module near the second port.

18. The method of claim 15 wherein the second port is a needle-less port that is accessed through luer connection and the device is a catheter device having a hollow portion with a catheter needle attached.

19. The method of claim 18 wherein the module is color coded for a gauge of luer connection used for the needle-less port.

20. The method of claim 12 further comprising the step of configuring interior surfaces of the module, the device, the vent and the filter to be substantially flush with each other forming an interior volume that enhances air flow and fluid flow.