Catheter assembly and pierced septum valve

A pierced septum valve is disclosed herein. The pierced septum valve includes a septum that is located within a lumen of a body. A septum activator is positioned proximal the septum within the lumen of the body. A seal is disposed between an outer surface of the septum activator and the body to seal the portion of the septum activator distal the lumen from the portion of the septum activator proximal the lumen. One or more vents are disposed between the seal and the lumen of the body to permits the passage of air but not blood past the seal.

BACKGROUND

Catheters are commonly used for a variety of infusion therapies. For example, catheters are used for infusing fluids, such as normal saline solution, various medicaments, and total parenteral nutrition into a patient; withdrawing blood from a patient; or monitoring various parameters of the patient's vascular system. Catheters are typically coupled to a catheter adapter that supports catheter and provides for an attachment to IV tubing. Generally, following placement of the catheter into the vasculature of a patient, the catheter adapter may be coupled to a fluid source via a section of IV tubing to infuse fluids into the patient.

In order to verify proper placement of the catheter in the blood vessel, the clinician generally confirms that there is “flashback” of blood from the patient's vasculature into a flashback chamber of the catheter or catheter adapter. Once proper placement of the catheter is confirmed, the clinician must attach the catheter adapter to a section of IV tubing, or continue to manually occlude the vein to prevent undesirable exposure to blood. The process of coupling the catheter adapter to the section of IV tubing requires the clinician to awkwardly maintain pressure on the vein of the patient while simultaneously coupling the catheter adapter and the IV tubing. A common, yet undesirable practice is to permit blood to temporarily and freely flow from the catheter adapter while the clinician locates and couples the IV tubing to the catheter adapter. Another common practice is to attach the catheter adapter to the IV tubing prior to placing the catheter into the vein of the patient. While this method may prevent undesirable exposure to blood, positive pressure from the IV tubing into the catheter can does not permit desirable flashback and thus reduces a clinician's ability to confirm proper catheter placement.

Accordingly, there is a need in the art for a catheter assembly that permits controlled, desirable flashback without the risk of encountering undesirable exposure to blood. Such a catheter assembly is disclosed herein.

SUMMARY

In order to overcome the limitations discussed above, the present invention relates to a pierced septum valve that provides selective activation of fluid flow through the catheter assembly while minimizing or eliminating blood exposure. Furthermore, confirmation of catheter placement can be enhanced with an additional flash chamber that is created by including a seal around the exterior of the septum activator. The combination of the pierced septum valve and the seal about the septum activator can provide a longer flashback period in which clinicians can assure that a catheter is properly placed in a blood vessel of a patient.

In one aspect, a pierced septum valve includes a septum, a septum activator, a seal and one or more vents. The septum is disposed within a lumen of a body. A septum activator is disposed proximal the septum within the lumen of the body. A seal is disposed between an outer surface of the septum activator and the body. The seal seals the portion of the septum activator distal the seal from the portion of the septum activator proximal the seal. One or more vents are disposed between the seal and the lumen of the body, the one or more vents each having a cross sectional area that permits the passage of air but not blood.

Some implementations include one or more of the following aspects. The cross sectional area of each vent can be between 0.0001 to 0.0003 inches2. The one or more vents can include six or more vents. The seal can encircle the septum activator. The one or more vents can be formed in the exterior of the seal. The one or more vents can be formed through the seal. The one or more vents can be channels formed in the body. The body can be a catheter adapter and the lumen of the body can extend through the catheter adapter. The seal can have an outer diameter greater than or equal to an inner diameter of the lumen. The seal can include an elastomeric material. The seal can be disposed about a proximal portion of the septum activator.

In another aspect, a catheter assembly includes a catheter adapter, a septum, and a septum activator, a seal, one or more flow restrictors, and one or more vents. The catheter adapter has a lumen extending therethrough. The septum is disposed within the lumen. One or more flow restrictors are disposed between the septum and the catheter adapter. A septum activator is disposed within the lumen proximal the septum. A seal is disposed between an outer surface of the septum activator and the catheter adapter. The seal seals the portion of the septum activator distal the seal from the portion of the septum activator proximal the seal. One or more vents are disposed in the seal.

Some implementations include one or more of the following aspects. The one or more vents disposed in the seal can each have a cross sectional area between 0.0001 to 0.0003 inches2. The one or more flow restrictors include one or more openings each having a cross sectional area of greater than 0.0003 inches2. The volume exterior the septum activator between the septum and the seal can form a flashback chamber. The septum activator can have a substantially tubular-shaped body with a lumen extending therethrough. The seal can have an outer diameter greater than or equal to an inner diameter of the lumen at the locations. The seal can be disposed about a proximal portion of the septum activator. The seal can include an elastomeric material.

In another aspect, a catheter assembly includes a catheter adapter, a septum, a septum activator, an annular seal, and one or more vents. The catheter adapter has a lumen extending therethrough. The septum is disposed within the lumen. One or more flow restrictor channels are disposed between the septum and the catheter adapter. The cross sectional area of each of the flow restrictor channels is greater than 0.0003 inches2. The septum activator is disposed within the lumen proximal the septum, the septum activator has a substantially tubular-shaped body. An annular seal is disposed between an outer surface of the septum activator and an inner surface of the lumen. The seal encircles a proximal portion of the septum activator. One or more vents are disposed between the seal and the lumen of the body. The one or more vents each have a cross sectional area between 0.0001 to 0.0003 inches2.

DETAILED DESCRIPTION OF THE INVENTION

Embodiment of the present invention will be best understood by reference to the drawings, wherein like reference numbers indicate identical or functionally similar elements. It will be readily understood that the components of the present invention, as generally described and illustrated in the figures herein, could be arranged and designed in a wide variety of different configurations. Thus, the following more detailed description, as represented in the figures, is not intended to limit the scope of the invention as claimed, but is merely representative of presently preferred embodiments of the invention.

Referring now toFIG. 1, a catheter assembly10is illustrated. The catheter assembly10generally includes a catheter12coupled to a distal end16of a catheter adapter14. The catheter12and the catheter adapter14are integrally coupled such that an inner lumen of the catheter adapter14is in fluid communication with an inner lumen of the catheter12. The catheter12generally comprises a biocompatible material having sufficient rigidity to withstand pressures associated with insertion of the catheter into a patient.

In some embodiments, as shown, the catheter12is an over-the-needle catheter that is made of a flexible or semi-flexible polymer material and which may be used in combination with a rigid introducer needle22. The rigid introducer needle22enables the insertion of the non-rigid over-the-needle catheter into a patient. The introducer needle22can be coupled to a needle hub26that is selectively coupled to the proximal end18of the catheter adapter14. The introducer needle22is typically inserted through the catheter12such that a tip of the needle22extends beyond the tapered tip20of the catheter12. Insertion of the introducer needle22into the vein of the patient creates an opening in the vein through which the tapered tip20of the catheter12is inserted. The outer surface of the tapered tip20enables gradual insertion of the catheter12into the opening.

In other embodiments, the catheter12is not an over-the-needle catheter, but comprises a rigid, polymer material, such as vinyl. Rigid catheters can include a beveled cutting surface that is utilized to provide an opening in a patient to permit insertion of the catheter12into the vascular system of the patient. Accordingly, in some embodiments, the catheter12comprises a metallic material, such as titanium, stainless steel, nickel, molybdenum, surgical steel, and alloys thereof. Still, in other embodiments, surgically implanted catheters may also be used in combination with the present invention.

The catheter12can be a peripheral-type intravenous catheter that generally comprises a short or truncated catheter for insertion into a small peripheral vein. Such catheters generally comprise a diameter of about a 14-gauge catheter or smaller (on a Stubs scale), and is between about 13 mm to 52 mm in length. Peripheral intravenous catheters are typically designed for temporary placement. The short length of the catheter facilitates convenient placement of the catheter. In other embodiments, the catheter12is a midline or central catheter, which may be longer and used for more extended periods.

Referring now toFIG. 2, once the catheter12is inserted into the vein of the patient, the introducer needle22is removed proximally from the catheter12to provide a fluid conduit through the interior lumen36of the catheter12, which can be connected to a fluid source. In some embodiments, a portion of the catheter12and/or catheter adapter14can be connected to a section of intravenous tubing40to further facilitate delivery of a fluid to or removal of a fluid from a patient. In some embodiments, a proximal end18of the catheter adapter14includes a flange32. The flange32provides a positive surface that may be configured to enable coupling of an intravenous tubing40or patient conduit to the catheter assembly10. In some embodiments, the flange32includes a set of threads30. The threads30are generally provided and configured to compatibly receive a complementary set of threads44comprising a portion of a male luer or conduit coupler42. The conduit coupler42is generally coupled to an end portion of the patient conduit40in a fluid-tight manner. In some embodiments, an inner portion of the conduit coupler42is extended outwardly to provide a probe member46.

The probe member46can be compatibly inserted within a proximal end18of the catheter adapter14to activate the septum therein, thus opening a fluid path within the catheter adapter14. In some configurations, following insertion of the probe member46into the proximal end22of the catheter adapter14, the conduit coupler42is interlock with the coupler42and the flange28(via the sets of threads30and44), such as by rotation. During the process of interlocking the coupler42and the flange28, the probe member46is advanced into the lumen36of the catheter adapter14to an inserted position (as shown inFIG. 6). As shown inFIG. 5, the intravenous tubing40is connected to the catheter adapter14, the probe member46advances into the lumen36of the catheter adapter14, forcing a septum activator80therein to pierce through the septum50. Piercing the septum50opens the septum and provides a fluid path through which fluids from the intravenous tubing40to flow through the pierced septum50and the catheter12into the patient. The process of piercing the septum50is described in detail below. As will be understood, prior to the insertion of the probing member46, the inner lumen36of the catheter adapter14is sealed to avoid blood exposure through from flashback.

Reference will now be made toFIGS. 3 and 4.FIG. 3depicts an exploded, cross-sectional view of a catheter assembly10.FIG. 4depicts a cross-sectional view of an assembled catheter assembly10. The septum activator80ofFIG. 4has an alternative structure to that ofFIG. 3, as is explained below. These figures, along withFIG. 6, depict embodiments of pierced septum valves, which include a septum having a slit that is opened and closed by the advancement and retraction of a probe-like septum activator therethrough.

As shown, in some embodiments, a septum50is positioned within the inner lumen36of the catheter adapter14to control the flow of fluid therein. The septum50generally comprises a flexible or semi-flexible polymer plug having an outer diameter that is configured to compatibly sit within a groove or channel60formed on an inner surface66of the catheter adapter14. In some embodiments, the septum50is barrel-shaped and has a barrier member52on its distal end and a cavity54within its a proximal end. When positioned within the channel60, the barrier member52of the septum50divides the inner lumen36of the catheter adapter14into a forward fluid chamber62and a rearward fluid chamber64. Thus, the presence of the septum50can limit passage of fluid between the forward and rearward fluid chambers62and64.

In some embodiments, the barrier member52of the septum50includes a slit56. The slit56can provide selective access or flow of a fluid through the barrier surface52as it opens (activates) and closed (deactivates) in response to the septum activator80. In some embodiments, the slit56is configured to remain in a closed, fluid-tight position until activated or opened by advancing a septum activator80through the slit56in a distal direction72. In some instances, the barrier member52comprises a single slit56. In other instances, the barrier member52is modified to include multiple slits56, such as two slits56forming a cross or x-shape. In other instances, the barrier member52is modified to include three slits56forming a Y-shape.

The septum activator80comprises a probe-like structure serves to activate and deactivate the septum50in response to the insertion and removal of the probe member46. The Septum activator80can be primarily housed in the rearward chamber64of the catheter adapter14, proximal the septum50. In some embodiments, the septum activator80is a tubular body82having a distal end84and a proximal end86. The tubular body82can be made of a rigid or semi-rigid material, such as a plastic or metallic material. The tubular body82can have an inner lumen88that facilitate flow of a fluid and/or liquid through the septum activator80when the septum activator80pierces through the slit56of the septum50.

The distal end84of the tubular body82can be configured to be compatibly inserted into the cavity54within the proximal side of the septum50so that it is positioned where it can pierce through the slit56of the barrier member52to form a fluid path therethrough. The distal end84further includes a leading surface90that can be inserted through the opening54of the septum50to a position proximal to the barrier member52of the septum50, as shown inFIG. 6. When forced distally, the leading surface90advances through the slit56as the septum activator80is moved between a deactivated position, as shown inFIG. 4, to an activated position, as shown inFIG. 5.

To properly align the septum activator80within the inner lumen36of the catheter adapter14, one or more alignment structures can be included between the outer surface of the septum activator80and the inner surface66of the catheter adapter14. For example, as shown inFIG. 4, one or more alignment fins110can protrude from the outer surface of the septum activator80and inserted within one or more alignment groove112formed within the inner surface66of the catheter adapter14. As the septum activator translates longitudinally within the catheter adapter, the one or more alignment fins110each track within the one or more alignment groove112to maintain septum activator80properly aligned within the catheter adapter14. In some configurations there are three, four, five, or six alignment fins110, each inserted within one of a like number of alignment grooves112.

In addition to activating the septum50, the septum activator80can form part of a flashback chamber116that provides an extended flashback indication to clinicians. Flashback generally occurs when the introducer needle22and/or the catheter12enter a blood vessel of a patient, piercing the blood vessel, and opening a fluid path through the catheter12. The patient's blood pressure forces blood out the blood vessel into the catheter assembly10. When the catheter adapter14or a portion thereof is transparent or semi-transparent, as it is in some embodiments, blood flow through its inner lumen36is observable and can indicate to a clinician that the catheter12is currently located within the blood vessel of the patient. If blood flow stops, the clinician can understand that the catheter12is no longer located within the blood vessel or that some other factor is restricting blood flow through the catheter12. Thus, a flashback that can last long enough for a clinician to properly place a catheter is desirable.

Referring toFIG. 4, in some embodiments, the blood generally enters the catheter assembly10and follows a flashback path114through the catheter assembly10. The fluid path114enters into the forward chamber62, which can be a first flashback chamber since it includes the volume that can be observed to be filled with blood. Next, blood flows through flow restrictors70disposed around the septum50and enters the flashback chamber116, which can be a second flashback chamber. In instances where the catheter adapter14or a portion thereof is transparent or semi-transparent, a clinician can observe this flow of blood filing these chambers, which indicates proper placement of the catheter12.

As mentioned, during flashback, blood enters the flashback chamber116through one or more flow restrictors70interposed between the septum50and the inner surface66of the catheter adapter14to provide a flow path for flashback. Generally, the septum50sits within a groove or channel60that comprises a recessed portion of the inner surface66of the catheter adapter14. The outer diameter of the septum50can compatibly and securely sit within the channel60. For example, in some embodiments the outer diameter of the septum50is selected to be both slightly smaller than the diameter of the channel60and slightly larger than the diameter of the inner lumen16. As such, the septum50is retained within the channel60during use of the catheter assembly10. The flow restrictor70can permit the passage of air and fluid therethrough, while generally regulating the flow rates. The size of the cross-sectional area of each flow restrictor can at least partially control the rate of fluid flowing therethrough. For example, as the cross-sectional area of the flow restrictors70increases, the potential rate of fluid flow through the flow restrictors70increases. Likewise, flow restrictors70having smaller cross sectional areas will decrease the flow of fluid therethrough. The sizes and configurations of flow restrictors70and other components are described in detail below.

The septum activator80in combination with the catheter adapter14and the septum50define the flashback chamber116, shown inFIG. 4. In some configurations, the outer surface92of the septum activator80provides a fluid barrier that prevents fluid from flowing between the inner lumen88of the septum activator80and the volume of space around the outer surface92of the septum activator80. Accordingly, as shown, in some instances, the septum activator80is a solid tube having only two openings: a proximal and a distal opening.

As fluid enters the flashback chamber116, a seal98disposed between the septum50and the inner surface66of the catheter adapter14can prevent the fluid from flowing out the proximal end of the catheter adapter14. In some embodiments, the seal98encircles the septum activator80, as shown. In some embodiments, the seal98is coupled to the outer surface92of the septum activator80to prevent the proximal flow of fluids past the seal98. In other embodiments, the seal98can be coupled to the inner surface66of the catheter adapter14. By adjusting the location of the seal98, the volume of the flashback chamber116increases or decreases. Thus, the seal98can be positioned at various locations between the proximal and distal ends of the septum activator80. For instance, the seal98can be disposed on a proximal portion of the septum activator80, such as the proximal half of the septum activator80, as shown. More specifically, in a non-limiting example, the seal98is disposed on the proximal end86of the septum activator80, as shown inFIG. 8, which is described below. Further, the seal98can circumscribe a portion of the outer surface92of the septum activator80in a ring-like fashion, as shown, to seal the area around a portion of the septum activator80.

In some embodiments, the seal98can provide a fluid-tight barrier about the septum activator80that prevents blood from leaking through the proximal end of the flashback chamber116and out the catheter assembly10. For instance, the seal98can have an outer diameter greater than or equal to the inner diameter of the lumen36of the catheter adapter14to block fluid flow through the entire area between the septum activator80and the catheter adapter14. The seal98can also be made of a flexible material so that it can adequately conform to the inner surface66of the catheter adapter13to form a seal thereon. Accordingly, the seal98can comprise a non-rigid material, such as an elastomeric material. In other instances, the seal98is made of other flexible, semi-flexible, or semi-rigid materials that can provide a fluid-tight seal between the catheter adapter14and the septum activator80.

Initially during flashback, blood flowing into the catheter12forces air to flow through the flow restrictors70. This initial infusion of blood can be very quick as blood rushes through the catheter12into the forward chamber62. The forward chamber62can serve as a first flashback chamber that provides a first indication to clinicians that blood is flowing into the catheter assembly10. By observing this flow of blood, a clinician can verify that the catheter12has entered a blood vessel. However, in some instances, the time in which this initial flashback occurs is very quick and not long enough for a clinician to verify proper catheter placement. Accordingly, in some configurations, a second flashback chamber116is provided on the proximal side of the septum50that provides extended flashback indications. Accordingly, air and blood from within the forward chamber62can flow through the flow restrictors70disposed between the septum50and the catheter adapter14into the second flash chamber116. Because the size of the flow restrictors70controls the flow of blood therethrough, the rate of flashback into the second flashback chamber116can be regulated to provide a longer average flashback periods.

When blood begins to flow into the catheter assembly, a positive pressure develops within the forward chamber62, the first flashback chamber, and the second flashback chamber116. This pressure can reduce or prevent the flow of blood into the catheter assembly10, thus preventing a desired flashback of the patient's blood into the catheter adapter14. Thus, some embodiments include features or elements to enable airflow through or around the seal98, to relieve this positive pressure by permitting air, but not blood, to exit therethrough. As such, some embodiments of the present invention provide a complete observable flashback, as generally desired for infusion procedures.

In some embodiments, the seal98of the septum activator98is modified to include one or more vents100. In other embodiments, one or more vents120(shown inFIG. 6), in the form of channels, are interposed between the seal98and the inner surface66of the catheter adapter14. These vents100relieve the positive pressure within the flashback chambers62,116by providing an access for air to bypass the seal98into the exterior environment. In some embodiments, the vents100are constructed by removing portions of the seal98surface, resulting in a plurality of generally parallel grooves. A close-up perspective view of a seal98having multiple vents100is depicted inFIG. 7. In other embodiments, the vents100are formed as channels through the seal98rather than on the surface of the seal98.

In some embodiments, the rate at which air and/or fluid flows through the vents100in the seal98is adjusted by manufacturing the catheter adapter14to include a greater or lesser number of vents100or by changing the cross-sectioned area of the vents100. Thus, in some embodiments the rate at which air and/or fluid flows out of the second flashback channel116is increased by manufacturing a catheter adapter14to have either an increased number of vent100, or vents100with a greater cross-sectioned area. Conversely, in other embodiments the rate at which air and/or fluid flows from the second flashback chamber116is decreased by manufacturing a catheter adapter14with either a decreased number of vents100, or vents100having a lesser cross-sectioned area.

One having skill in the art will appreciate that the blood pressure of the patient is largely responsible for the rate at which blood and air flow through the septum50and the vents100in or around the seal98. As such, the flow rate through the system is affected by the combined effective hydraulic diameter of all flow paths. Thus, in some embodiments, the hydraulic diameter of the vents100is modified to increase or decrease the rate of flow through the catheter assembly10. In other embodiments, the hydraulic diameter of the vents100are decreased thereby resulting in substantially reduced or stopped flow through the ventilation means. The governing equation for controlling the flow rate through the ventilation means is given in Equation 1, where BP is the blood pressure, A is the surface area of the ventilation means, ó is the surface tension of the blood, and P is the perimeter of the ventilation means.
BP(A)=σ(P)  Equation 1:

Thus, according to Equation 1, when the perimeter of a vent is small, the vents100will allow air venting, but will prevent blood flow due to the relatively high surface tension (σ) of blood. However, when the perimeter of the vent is increased, the surface tension between the blood and the vent100is decreased thereby enabling the blood to slowly leak through the vents and around the septum to provide desirable, yet controlled flashback. Therefore, by adjusting the variable of Equation 1, a desired flow will be achieved. Thus, based on the size and/or number of vents around the septum, the catheter assembly design will provide customized, controlled, and predictable blood flow through the seal100.

In some embodiments, the one or more vents100are designed to allow the flow of air and stop the flow of blood. In some embodiments, the number of vents100is between 1 and 40. In other embodiments, the number of vents100is between 1 and 20. In some embodiments, six or more vents100are included. While in other embodiments, five or fewer vents100are included. Accordingly, in some embodiments, the vents100have a cross sectional area between about 0.000007 to 0.00004 inches2. In other embodiments, the vents100have a cross sectional area between about 0.00001 to 0.00003 inches2. In other embodiments, the vents100have a cross sectional area of about 0.00002 inches2. For instance, in some embodiments, the vents100have a height of about 0.001 to 0.003 inches and a width of about 0.010 inches. In other embodiments, the vents have a height of about 0.002 to 0.003 inches and a width of about 0.005 inches.

Similarly, the one or more flow restrictors70between the septum50and the inner surface66of the catheter adapter14can be specifically configured to permit blood and air to pass therethrough at an estimated range of flow rates. For instance, the one or more flow restrictors70can permit blood to flow therethrough at a rate between about 10 to 200 ml/hr. In other instances, the one or more flow restrictors70can permit blood to flow therethrough at a rate between about 15 to 150 ml/hr. In yet other instances, the one or more flow restrictors70can permit blood to flow therethrough at a rate between about 50 to 100 ml/hr. At these rates, the rate of blood flow into the flashback chamber116can be paced to provide a clinician with adequate time to correctly locate the catheter within a patient's blood vessel. Accordingly, in some embodiments, the flow restrictors70have a cross sectional area greater than 0.00003 inches2. In other embodiments, the flow restrictors70have a cross sectional area greater than 0.00004 inches2. In other embodiments, the vents100have a cross sectional area of about 0.0001 inches2. In other embodiments, the vents100have a cross sectional area of about 0.001 inches2.

Referring now toFIG. 5a cross-sectional view of the catheter assembly10is shown following activation of the septum50via the septum activator80. Upon insertion of the coupler42into the proximal opening26of the catheter adapter14, the probe member46of the coupler42contacts the contact surface96of the septum activator80. The septum activator80is advanced in a distal direction72as the coupler42is further inserted into the lumen36of the catheter adapter14. As the coupler42is advanced farther into the lumen36, the probing surface92of the septum activator80passes through the barrier member52of septum50. As such, the probing surface92of the septum activator80is positioned within the forward chamber62providing a fluid pathway through the opened slit56of the septum50.

During septum activation, the volume of the flashback chamber116decreases as the septum activator80advances in the distal direction72. The decrease in volume can create a positive pressure within the flashback chamber116that can cause fluids within the flashback chamber116to flow back through the flow restrictors70into the forward chamber62, along the fluid flow path115. This fluid can then be flushed out the catheter assembly10with the infusion of fluids from the intravenous tubing40.

In some embodiments, the catheter assembly10is configured to permit the septum activator80to return to a deactivated position entirely within the rearward chamber64following removal of the coupler42from the catheter adapter14. Thus, when the coupler46is removed or detached from the catheter assembly10, the fluid pathway through the septum50is reclosed.

Referring will now be made toFIG. 6, which depicts a catheter assembly10similar to that ofFIG. 4. However, as shown, in some embodiments, the seal98does not include vents100. Rather, as shown inFIG. 6, one or more vents120are formed into the inner surface66of the catheter adapter14. In some configurations, the one or more vents120extend along the length of the inner surface66of the catheter adapter14at least at each location where the seal98contacts the catheter adapter14as it is moved from a deactivated position to an activated position. This configuration can permit air venting through the one or more vents120regardless of the location of the septum activator80. In other configurations, the one or more vents120extend only across the location where the seal98contacts the inner surface66of the catheter adapter14in a deactivate position, the position shown inFIG. 6. As mentioned, the dimensions of the vents120can be selected to permit the flow of air but not gas therethrough. These dimensions can be substantially similar to those referenced above for the vents100within the seal98.

Referring will now be made toFIG. 8, which depicts a septum activator80that has an alternative seal configuration. As shown, the septum activator80includes a tubular body82with a distal end84and a proximal end86. A seal130is disposed on the distal end86of the septum activator80, which will provide the largest possible length of flashback chamber116. Vents132are formed in the seal similar to those previously mentioned. In some embodiments, the seal130is integrated into the septum activator, such that the two form a single piece structure. In some embodiments, the septum activator80and the seal130are made of the same material. In other embodiments, the septum activator80and the seal130are made of different materials that are connected in a fluid-tight manner.

Referring now toFIG. 9, an embodiment of a septum104is shown. In some embodiments, an outer surface108of the septum104is modified to include a plurality of recessed grooves106. The recessed grooves106provide pathways between the forward and rearward chambers62and64through which air and/or fluid may flow. Thus, in some embodiments, the channel60does not include air flow restrictor channels70, but rather the outer surface108of the septum104is modified to provide desired flow between the forward and rearward chambers62and64. The shape and size of these grooves can be selected, as mentioned, to provide the desired flow rate therethrough. For instance, the one or more flow restrictors132can permit blood to flow therethrough at a rate between about 10 to 200 ml/hr. In other instance, the one or more vents132can permit blood to flow therethrough at a rate between about 15 to 150 ml/hr. In yet other instances, the one or more vents132can permit blood to flow therethrough at a rate between about 50 to 100 ml/hr.

From the foregoing, it can be seen that a pierced septum valve can provide selective activation of fluid flow through the catheter assembly while minimizing or eliminating blood exposure. Additionally, the pierced septum valve can enhance a clinician's ability to confirm catheter placement by providing an additional flash chamber between a seal around the exterior of the septum activator and the septum.