Patent Description:
The present disclosure generally relates to blood draw and administration of parenteral fluids to a patient, and particularly to systems and non claimed methods to reduce hemolysis in PIVC blood draw using a flow restriction device.

Catheters are commonly used for a variety of infusion therapies. For example, catheters may be used for infusing fluids, such as normal saline solution, various medicaments, and total parenteral nutrition, into a patient. Catheters may also be used for withdrawing blood from the patient.

A common type of catheter is an over-the-needle peripheral intravenous ("IV") catheter (PIVC). As its name implies, the over-the-needle catheter may be mounted over an introducer needle having a sharp distal tip. A catheter assembly may include a catheter hub, the catheter extending distally from the catheter hub, and the introducer needle extending through the catheter. The catheter and the introducer needle may be assembled so that the distal tip of the introducer needle extends beyond the distal tip of the catheter with the bevel of the needle facing up away from skin of the patient. The catheter and introducer needle are generally inserted at a shallow angle through the skin into vasculature of the patient.

For blood withdrawal or collecting a blood sample from a patient, a blood collection container may be used. The blood collection container may include a syringe. Alternatively, the blood collection container may include a test tube with a rubber stopper at one end. In some instances, the test tube has had all or a portion of air removed from the test tube so pressure within the test tube is lower than ambient pressure. Such a blood collection container is often referred to as an internal vacuum or a vacuum tube. A commonly used blood collection container is a VACUTAINER® blood collection tube, available from Becton Dickinson & Company.

The blood collection container may be coupled to the catheter. When the blood collection container is coupled to the catheter, a pressure in the vein is higher than a pressure in the blood collection container, which pushes blood into the blood collection container, thus filling the blood collection container with blood. A vacuum within the blood collection container decreases as the blood collection container fills, until the pressure in the blood collection container equalizes with the pressure in the vein, and the flow of blood stops. In some instances, blood is drawn into the collection container by withdrawing the plunger of a syringe.

Unfortunately, as blood is drawn into the blood collection container, red blood cells are in a high shear stress state and susceptible to hemolysis due to a high initial pressure differential between the vein and the blood collection container. Hemolysis may result in rejection and discard of a blood sample. The high initial pressure differential can also result in catheter tip collapse, vein collapse, or other complications that prevent or restrict blood from filling the blood collection container. Furthermore, blood spillage during and/or after blood draw commonly occurs.

In some instances, withdrawing a plunger of a syringe coupled to the catheter may exert an unintended pressure on the blood such that the red blood cells are in a high shear stress state, which may result in hemolysis. Further, the process of withdrawing the plunger of a syringe to draw blood into the blood collection container is reliant upon the control and skill applied by the user, which may vary among different users.

<CIT> discloses a bidirectional valve for medical use or the like providing different threshold opening pressures in different directions using a valve seat and flapper construction providing improved characterization in operation in contrast to cross-slit valves often used for bidirectional operation. A valve disk supported in a central annular region provides movable portions engaging in valve seats at a peripheral region and a central region.

Preferable embodiments are further laid out in the dependent claims. The present disclosure provides a flow restriction device which is not according to the present invention, comprising: a proximal housing comprising a first end portion forming a proximal port, a second end portion, and a passage extending through the first and second end portions; a distal housing comprising a first end portion, a second end portion forming a distal port, and a passage extending through the first and second end portions; a flow insert positioned in a cavity formed between the proximal housing and the distal housing, the flow insert comprising a fluid passage extending therethrough, the fluid passage comprising a first segment formed by an outer surface of the flow insert, and a second segment formed by an inner surface of the flow insert; a resilient valve positioned between the outer surface of the flow insert and the distal housing, the resilient valve comprising a first end having an inner portion and an outer portion, the inner portion aligned with the second segment of the fluid passage of the flow insert, and the outer portion aligned with the first segment of the fluid passage of the flow insert; wherein the inner portion of the resilient valve is flexible, relative to the proximal housing, such that in a first position of the resilient valve, the inner portion is spaced apart from the flow insert by a first distance to permit a fluid to move between the first and second segments of the fluid passage, and in a second position, the inner portion is spaced apart from the flow insert by a second distance to resist movement of the fluid between the first and second segments of the fluid passage.

The present invention provides a flow restriction device according to claim <NUM>, comprising: a flow insert comprising a fluid passage extending therethrough, the fluid passage comprising a first segment formed by an outer surface of the flow insert, and a second segment formed by an inner surface of the flow insert; a resilient valve comprising a first end engaged against the outer surface of the flow insert, the first end having an inner portion aligned with the second segment of the fluid passage, and an outer portion aligned with the first segment of the fluid passage, and an aperture that extends through the resilient valve, from the first end to a second end of the resilient valve; wherein the inner portion of the resilient valve is flexible, relative to the flow insert such that in a first orientation of the resilient valve, the inner portion is spaced apart from the flow insert g by a first distance to permit a fluid to move from the first segment toward the second segment of the fluid passage, and in a second orientation of the resilient valve, the inner portion is spaced apart from the flow insert by a second distance to resist movement of the fluid from the first segment toward the second segment of the fluid passage.

Blood draw via a vascular access device has drawn increasing attention attributed to minimized needle sticks and improved operation efficiency as compared with traditional blood draw methods with venipuncture. Current blood draw using a peripheral intravenous catheter (PIVC) has seen some challenges, one of the most critical is hemolysis related blood quality. In particular, with currently existing PIVC products in the market, along with the standard connection (such as a short extension set and a needleless connector), and blood collection devices (such as a Vacutainer), the shear stress exerted onto blood cells tends to be on the verge of hemolyzing.

Various embodiments of the present disclosure are directed to providing systems and non claimed methods to address hemolysis in PIVC blood draw with a hemolysis reduction accessory (also referred to herein as a flow restriction device) which can be pre-attached to the PIVC and decrease a flow rate to reduce a risk of hemolysis. The hemolysis-reduction accessory is advantageously compatible with PIVC placement and does not necessitate change to any of the existing operations. The hemolysis-reduction accessory of the various embodiments described herein is potentially applicable to a wide variety of PIVC products, and compatible with existing blood collection devices and infusion disposables.

Various embodiments of the present disclosure focus on effective flow rate reduction with the add-on hemolysis-reduction accessory (also referred to herein as a flow restriction device) that regulates the overall flow rate of the entire fluid path as blood cells travel through. The flow restriction device can be either assembled with the PIVC or co-packaged with the PIVC. As such, there is no additional operation during catheter placement since the device can permit blood flashback. The clinician may connect a blood collection device to a port or opening of the accessory and can then draw blood to the intended volume. After blood draw, the clinician may disconnect and discard the flow restriction device and the blood collection device together. As such, this flow restriction device can be either for single blood draw or stay inline throughout indwell.

The flow restriction devices and associated blood collection systems of the various embodiments described herein additionally provide further advantages over currently existing blood collection systems. For example, flow restriction devices described herein allow for hemolysis-reduction function to be integrated for PIVC blood draw. Further, the flow restriction devices described herein are compatible with PIVC placement and allow for seamless blood draw at insertion. Additionally, since the flow restriction devices are an add-on which can be easily incorporated without any changes to existing PIVC, there is minimal impact to clinical setting and operations. The present disclosure also provides flow restriction devices and associated blood collection systems that can prevent the hemolysis of blood due to high suction pressure by reducing a cross-sectional area or closing a blood flow path to reduce the flow rate of the blood moving therethrough when the suction pressure goes beyond desired value or range. When the suction pressure returns to a desired value or range, the features of the present disclosure can permit the flow rate of the blood through the blood flow path to increase.

Flow restriction devices of the present disclosure can include a surface forming a fluid passage, and a resilient valve positioned adjacent to or along at least a portion of the fluid passage. At least a portion of the resilient valve is movable or can bias toward or away from the fluid passage. In a first orientation or position of the resilient valve, a fluid such as blood can move along a fluid flow path that includes the surface forming the fluid passage, and between the surface and the resilient valve. In a second orientation or position of the resilient valve, at least a portion of the valve is moved or biased toward the surface forming the fluid passage such that a cross-sectional area of the fluid flow path between the surface and the resilient valve is decreased, relative to the first orientation. In the second orientation, movement of the fluid along the fluid flow path between the surface forming the fluid passage and the resilient valve is reduced or stopped, relative to the first orientation.

In some embodiments of the present disclosure, flow restriction devices can include a surface forming a fluid passage having a first segment and a second segment, and a resilient valve positioned adjacent to or between the first and second segments of the fluid passage, such that a fluid flow path extends between the resilient valve and the surface forming the fluid passage. In a first orientation of the resilient valve, a fluid can move along the fluid flow path between the first and second segments of the fluid passage, and in a second orientation, at least a portion of the valve is moved or biased toward the surface forming the fluid passage such that movement of the fluid along the fluid flow path between the first and second segments is reduced, relative to when the resilient valve is in the first orientation. In some embodiments of the present disclosure, movement of the fluid along the fluid flow path between the first and second segments is obstructed when the resilient valve is in the second orientation.

In some aspects of the present disclosure, flow restriction devices can include housing forming a cavity and at least a portion of the fluid flow path. The surface forming the fluid passage can be formed by a surface of the housing, such as an inner surface, and the resilient valve can be positioned in a cavity of the housing. In some embodiments, an inner surface of the housing can define the fluid passage and the cavity, and the resilient valve is positioned in a cavity. Some embodiments of the present disclosure include a housing having an inner surface forming a cavity, a resilient valve positioned within the cavity, and a flow insert positioned within the cavity and having a surface forming at least apportion of the fluid passage.

The fluid passage or a portion thereof can extend in a direction that is linear or non-linear. In some embodiments, any of a first or second segment of the fluid passage extends in direction that is linear, and the other of the first or second segment of the fluid passage extends in a direction that is non-linear. The non-linear direction can, for example, form a spiral or involute shape. The spiral or involute shape fluid passage can form a first segment portion of the fluid passage that extends radially inward to a second segment of the fluid passage. The spiral or involute shape of the fluid passage can extend around a longitudinal axis through a central portion of the second segment of the fluid passage.

In some embodiments of the present disclosure, the fluid passage or a portion thereof can form an angle between segments, where the angle can be between approximately <NUM> degrees and approximately <NUM> degrees. In some embodiments, the angle between segments is approximately <NUM> degrees.

<FIG> illustrates a vascular access device <NUM> including a peripheral intravenous catheter (PIVC) assembly <NUM>, a flow restriction device <NUM>, and a blood collection device <NUM>, in accordance with some embodiments of the present disclosure. The devices illustrated in <FIG> can be used, for example, in a syringe blood draw procedure. The flow restriction device <NUM> may be configured to reduce a likelihood of hemolysis during blood collection using the vascular access device <NUM> and the blood collection device <NUM>. In some embodiments, the vascular access device <NUM> may include a catheter assembly <NUM>. The catheter assembly <NUM> may include a catheter hub <NUM>, which may include a distal end <NUM>, a proximal end <NUM>, and a lumen extending through the distal end and the proximal end. The catheter assembly <NUM> may further include a catheter <NUM>, which may be secured within the catheter hub <NUM> and may extend distally from the distal end <NUM> of the catheter hub <NUM>. In some embodiments, the catheter assembly <NUM> may be a peripheral intravenous catheter (PIVC).

In some embodiments, the catheter assembly <NUM> may include or correspond to any suitable catheter assembly <NUM>. In some embodiments, the catheter assembly <NUM> may be integrated and include an extension tube <NUM>, which may extend from and be integrated with a side port <NUM> of the catheter hub <NUM>. A non-limiting example of an integrated catheter assembly is the BD NEXIVA™ Closed IV Catheter system, available from Becton Dickinson and Company. In some embodiments, a proximal end of the extension tube <NUM> may be coupled to an adapter, such as, for example, a Y-adapter <NUM>. In some embodiments, the flow restriction device <NUM> may be fluidly coupled to the Y-adapter <NUM>.

In some embodiments, the catheter assembly <NUM> may be non-integrated and may not include the extension tube <NUM>. In these and other embodiments, the flow restriction device <NUM> may be configured to couple to the proximal end <NUM> of the catheter hub <NUM> or another suitable portion of the catheter assembly <NUM>. In some embodiments, the flow restriction device <NUM> may be coupled directly to the catheter assembly <NUM>, eliminating the extension tube <NUM> and providing a compact catheter system.

<FIG> illustrates a perspective view of a flow restriction device <NUM> having a proximal housing <NUM> and a distal housing <NUM>, in accordance with some embodiments of the present disclosure. <FIG> illustrates an exploded view of the flow restriction device <NUM> having a proximal housing <NUM>, a distal housing <NUM>, a resilient valve <NUM>, and a flow insert <NUM>, and where the resilient valve <NUM> and the flow insert <NUM>, are configured to be positioned between the proximal and distal housings <NUM>, <NUM>. <FIG> illustrates a perspective view of the flow restriction device <NUM> with the proximal and distal housings <NUM>, <NUM> shown as being transparent to illustrate the resilient valve <NUM> and the flow insert <NUM> positioned within a cavity between the proximal and distal housings <NUM>, <NUM>. <FIG> illustrate a cross-sectional view of the flow restriction device <NUM> of <FIG>, along line <NUM>-<NUM>.

As illustrated in <FIG>, in some embodiments, the flow restriction device <NUM> includes a proximal housing <NUM> and a distal housing <NUM>. Each of the proximal and distal housings <NUM>, <NUM> include a port configured to couple a fluid flow path of the flow restriction device <NUM> with other devices, such as a vascular access device <NUM>, a blood collection device <NUM>, and/or a catheter assembly <NUM>. In some embodiments of the present disclosure, the distal housing <NUM> can include a first end portion <NUM> forming a distal port <NUM> of the flow restriction device, and the proximal housing <NUM> can include a second end portion <NUM> forming a proximal port <NUM> of the flow restriction device.

The distal port <NUM> can be configured to couple with a blood collection device, such a vascular access device <NUM> or a catheter assembly <NUM>, and the proximal port <NUM> can be configured to couple with a blood collection device <NUM> such as a syringe. In some embodiments of the present disclosure, any of the proximal and distal ports <NUM>, <NUM> can form any of a male or female luer connector. In some embodiments, the proximal port <NUM> is formed as female luer connector and the distal port <NUM> is formed as a male luer connector.

The distal port <NUM> can be formed by an inner surface <NUM> of the distal housing <NUM>. The inner surface <NUM> defines a passage <NUM> through the distal housing, with the passage extending from the first end portion <NUM> to a second end portion <NUM> of the distal housing.

The distal housing <NUM> can also include, in some embodiments, a wall <NUM> forming the first end portion <NUM> and having an inner surface <NUM> that forms a female connector. The distal housing <NUM> can also include a protrusion <NUM> that extends along the first end portion <NUM> of the distal housing and is positioned radially inward from the inner surface <NUM> of the wall such that an outer surface <NUM> of the protrusion is spaced apart from the inner surface <NUM> of the wall.

The protrusion <NUM> and the wall <NUM> form a connector of the flow restriction device configured to couple with another device positioned between the inner surface <NUM> of the wall and the outer surface <NUM> of the protrusion, where the passage <NUM> of the distal housing extends through the protrusion <NUM>.

In some embodiments of the present disclosure, the inner surface <NUM> of the wall can include a fastening structure configured to engage against and/or couple the flow restriction device <NUM> with another device. In some aspects, the fastening structure of the distal housing <NUM> can be a thread <NUM> that extends along the inner surface <NUM> of the wall. In some examples of the present disclosure, the fastening structure of the distal housing <NUM> can be the inner surface <NUM> of the wall configured to engage against another device to form an interference fit therebetween.

The second end portion <NUM> of the distal housing has an inner surface forming a bore that extends into the distal housing, in a direction from the second end portion <NUM> toward the first end portion <NUM>, to a recessed surface <NUM>. The passage <NUM> of the proximal housing extends through the recessed surface <NUM> into the bore.

The second end portion <NUM> of the distal housing can also include a flow channel <NUM> configured to be fluidly coupled with the passage <NUM>. The flow channel <NUM> extends into the recessed surface <NUM> to define another portion of the fluid flow path through the flow restriction device <NUM>.

The flow channel <NUM> includes a first or proximal end <NUM> that that intersects the passage <NUM> of the distal housing to fluidly couple the flow channel <NUM> with the passage <NUM>. The flow channel <NUM> extends in a direction away or radially outward from the passage <NUM>. The flow channel <NUM> also includes a second or distal end <NUM> that is configured to fluidly couple with another portion of the fluid flow path of the flow restriction device <NUM>.

The proximal housing <NUM> is configured to couple with the distal housing <NUM> to form another portion of the fluid flow path of the flow restriction device <NUM>. The fluid flow path of the proximal housing <NUM> can include the proximal port <NUM>. The proximal port is formed by an inner surface <NUM> of the proximal housing <NUM>. The inner surface <NUM> defines a passage <NUM> through the proximal housing, with the passage extending from a first end portion <NUM> to the second end portion <NUM> of the proximal housing.

In some embodiments of the present disclosure the first end portion <NUM> of the proximal housing has an inner surface forming a bore that extends into the proximal housing, in a direction from the first end portion <NUM> toward the second end portion <NUM>.

The proximal housing <NUM> and the distal housing <NUM> are configured to form a cavity therebetween, where the cavity is configured to receive a resilient valve <NUM> and a flow insert <NUM>. In some embodiments of the present disclosure, the resilient valve <NUM> and the flow insert <NUM> are positioned between the recessed surface <NUM> of the distal housing and the first end portion <NUM> of the proximal housing. In some embodiments, the resilient valve <NUM> and the flow insert <NUM> are positioned in the cavity formed between the proximal and distal housings <NUM>, <NUM>.

In some embodiments of the present disclosure, an outer surface <NUM> of the second end portion of the proximal housing can include a fastening structure configured to engage against and/or couple the flow restriction device <NUM> with another device. In some aspects, the fastening structure of the proximal housing <NUM> can be a thread <NUM> that extends along the outer surface <NUM> of the second end portion.

The resilient valve <NUM> is positioned between the proximal and distal housings <NUM>, <NUM>, and is configured to resist movement of a fluid along the fluid flow path of the flow restriction device <NUM>. The resilient valve <NUM>, which is illustrated in <FIG>, includes a first end <NUM> and a second end <NUM> where the second end <NUM> is opposite to the first end <NUM>. Additionally, an inner portion <NUM> and an outer portion <NUM> that extends around the inner portion <NUM> is defined along the first and second ends <NUM>, <NUM> of the resilient valve. The inner portion <NUM> is flexible, relative to the outer portion <NUM>, so that the inner portion <NUM> can move or bias when a force or pressure is exerted on the resilient valve.

In some embodiments of the present disclosure, the first end <NUM> of the resilient valve forms a convex surface along the inner portion <NUM>, and the second end <NUM> of the resilient valve forms a concave surface along the inner portion <NUM>. When the resilient valve <NUM> is positioned between the proximal and distal housings <NUM>, <NUM>, the inner portion <NUM> along the second end <NUM> is aligned with the passage <NUM> of the distal housing, and the inner portion along the first end <NUM> is aligned with another fluid passage of the flow restriction device <NUM>.

The resilient valve <NUM>, in some embodiments, is shaped as a disk having a radial center <NUM> and an outer perimeter <NUM> that extends around the center. In some aspects, the inner portion <NUM> is aligned with the center <NUM> of the resilient valve, and the outer portion <NUM> extends from the inner portion to the outer perimeter <NUM> of the resilient valve.

The resilient valve <NUM> includes an aperture <NUM> that extends through the first and second ends <NUM>, <NUM>, and is configured to form a portion of the fluid flow path of the flow restriction device <NUM>. The aperture <NUM> forms a portion of the fluid flow path that permits a fluid to move through the resilient valve <NUM>.

The aperture <NUM> can be located along the outer portion <NUM>, however, it should be understood that the present disclosure contemplates the aperture <NUM> positioned along any of the inner and/or outer portions <NUM>, <NUM>. In some embodiments of the present disclosure, a portion of the fluid flow path extends along any of the outer surface of the first end <NUM>, the second end <NUM>, the outer perimeter <NUM>, and/or the aperture <NUM>.

To align the resilient valve <NUM> with another portion of the flow restriction device <NUM>, the resilient valve <NUM> can include an alignment ridge <NUM>. In some embodiments, the alignment ridge <NUM> extends from the surface of the first end <NUM>, in a direction away from the second end <NUM>. The alignment ridge <NUM> can be configured to that when the resilient valve <NUM> is positioned next to the flow insert <NUM>, the alignment ridge <NUM> can engage against or be positioned within a complementary feature of the flow insert <NUM>. In some aspects, when the resilient valve <NUM> is positioned next to the flow insert <NUM>, and the alignment ridge <NUM> is positioned within or engaged against a complementary feature of the flow insert <NUM>, the aperture <NUM> of the resilient valve is aligned with and/or intersects a portion of the fluid flow path formed by the flow insert <NUM>.

Referring to <FIG>, the alignment ridge <NUM> is illustrated extending from the first end <NUM> of the resilient valve, in a direction away from the second end <NUM> of the resilient valve. The alignment ridge <NUM> is shaped as an elongate wall having a width and a length. The width of the alignment ridge <NUM> extends in a direction from the center <NUM> toward the outer perimeter <NUM> of the resilient valve, and the length of the alignment ridge <NUM> extends in a direction along the outer perimeter <NUM> of the resilient valve. The shape of the alignment ridge <NUM> along the first end <NUM> of the resilient valve is illustrated with a broken line B1 along the second end <NUM> of the resilient valve in <FIG> for reference.

It should be understood that although the alignment ridge <NUM> is illustrated as extending away from the first end <NUM> of the resilient valve, the present application contemplates that an alignment ridge can also be shaped as any of a concave surface and/or convex surface that extends from any of the first and/or second ends <NUM>, <NUM> of the resilient valve. In some embodiments of the present disclosure the alignment ridge can be any of a protrusion and/or indentation along the outer perimeter <NUM> of the resilient valve.

The resilient valve <NUM> is positioned adjacent to the flow insert <NUM> to form another portion of the fluid flow path between the resilient valve <NUM> and the flow restriction device <NUM>. To form the portion of the fluid flow path of the flow restriction device <NUM>, the flow insert <NUM> has an inner surface forming a fluid passage therethrough. The fluid passage includes a first segment <NUM> and a second segment <NUM>. The first segment <NUM> is formed by an outer surface <NUM> of the flow insert, and the second segment <NUM> is formed by an inner surface <NUM> of the flow insert.

In some embodiments of the present disclosure, the outer surface <NUM> is formed by a distal-most end surface of the flow insert <NUM> that is configured to engage against at least a portion of the resilient valve <NUM>. The outer surface <NUM> can be shaped as a planar surface configured to engage against the resilient valve to form a portion of the flow path therebetween.

The first segment <NUM> is formed by a channel that extends into the outer surface <NUM>, and along a direction that extends from an outer circumferential portion of the flow insert toward a longitudinal axis BB defined by the second segment <NUM> of the passage. The outer surface <NUM> can define a plane that is transverse, relative to the longitudinal axis BB.

The first segment <NUM> of the fluid passage for the flow insert extends along the outer surface <NUM> in a direction that is non-linear, such that the first segment <NUM> forms a spiral or involute shape in the direction toward the longitudinal axis BB. The first segment <NUM> of the passage can also be defined by a first end <NUM> located adjacent to the outer circumferential portion of the flow insert, and a second end <NUM> that intersects the second segment <NUM> of the passage.

The first segment <NUM> of the fluid passage can have a length between the first and second ends <NUM>, <NUM>, and a width that is transverse to the length. In some embodiments of the present disclosure, the length of the first segment <NUM> is approximately <NUM> inch (<NUM>), and the width of the first segment <NUM> is approximately <NUM> inch (<NUM>).

In some embodiment of the present disclosure, a portion of the fluid passage of the flow insert <NUM> is formed by a groove <NUM> that extends into the outer surface <NUM> of the flow insert, and extends between the first and second segments <NUM>, <NUM> of the fluid passage. The groove <NUM> can be configured to permit a fluid to move between the first and second segments <NUM>, <NUM> of the fluid passage when the resilient valve <NUM> moves or is biased toward the flow insert <NUM>.

The flow insert <NUM> can also include an alignment channel <NUM> configured to receive the alignment ridge <NUM> of the resilient valve therein. In some aspects of the present disclosure, the alignment ridge <NUM> and the alignment channel <NUM> are positioned on the resilient valve <NUM> and the flow insert <NUM>, respectively, so that the aperture <NUM> of the resilient valve is aligned with the first segment <NUM> of the passage, as illustrated by the broken line B2 in <FIG>.

Referring to <FIG>, and with continued reference to <FIG>, a cross-sectional view of the flow restriction device <NUM> is illustrated with the resilient valve <NUM> in a first position between the proximal and distal housings <NUM>, <NUM>. The resilient valve <NUM> is oriented with the second end <NUM> adjacent to or engaging against the recessed surface <NUM> of the distal housing, and the first end <NUM> adjacent to or engaging against the outer surface <NUM> of the flow insert.

Along the second end <NUM> of the resilient valve, the inner portion <NUM> is aligned with the passage <NUM> of the distal housing <NUM>, and the outer portion <NUM> is aligned with the flow channel <NUM>. The space formed along the flow channel <NUM> of the distal housing and the resilient valve <NUM> defines a portion of the fluid flow path. It should be understood that in some embodiments of the present disclosure, the flow channel can extend into the resilient valve to form a space between the resilient valve and the distal housing defining a portion of the fluid flow path.

The aperture <NUM> of the resilient valve is aligned with the flow channel <NUM> of the distal housing to permit a fluid to move through the resilient valve in a direction toward or away from the flow channel <NUM>. The aperture <NUM> of the resilient valve can aligned with the distal end <NUM> of the flow channel or along another portion of the flow channel <NUM>. In some embodiments of the present disclosure, the aperture <NUM> is aligned with the distal end <NUM> of the flow channel when the alignment ridge <NUM> of the resilient valve is engaged against or positioned within the alignment channel <NUM> of the flow insert.

Along the first end <NUM> of the resilient valve, the outer portion <NUM> and the aperture <NUM> are aligned with the first segment <NUM> of the passage, so that a fluid can move between the flow channel <NUM> and the first segment <NUM> of the passage by moving through the aperture <NUM>.

It should be understood that in some embodiments of the present disclosure, the aperture <NUM> can be formed as a channel or groove along the outer perimeter <NUM> of the resilient valve. Also, in some embodiments of the present disclosure, a portion of the fluid flow path extends around the outer perimeter <NUM> of the resilient valve instead of or in addition to extending through the resilient valve.

The inner portion <NUM> of the resilient valve is aligned with the second segment <NUM> of the passage to form a portion of the fluid flow path therebetween. When the resilient valve <NUM> is in the first position, the inner portion <NUM> of the resilient valve is spaced apart from the flow insert by a distance D1 to permit a fluid to move along the fluid flow path between the resilient valve <NUM> and the flow insert <NUM>. In some embodiments of the present disclosure the convex surface of the inner portion <NUM> defines a shoulder <NUM> configured to engage against a valve seat <NUM> of the flow insert, where the valve seat <NUM> is between the first and second segments <NUM>, <NUM> of the passage.

The fluid flow path through the flow restriction device <NUM>, when the resilient valve <NUM> is in the first position, is illustrated in <FIG>. A fluid, such as blood, can move through the distal port <NUM> of distal housing (Arrow A1). The fluid moves along the passage <NUM> toward the flow channel <NUM> of the distal housing. The fluid can then move along the flow channel <NUM> (Arrow A2) toward the aperture <NUM> of the resilient valve <NUM>. The fluid moves through the aperture <NUM> (Arrow A3) and enters into the first segment <NUM> of the fluid passage for the flow insert <NUM>.

Referring to <FIG> and <FIG>, the fluid can enter the first end <NUM> of the first segment <NUM> of the fluid passage, the location illustrated by way of reference with broken line B2. The fluid then moves along the first segment <NUM> along a spiral or involute shaped path toward the second segment <NUM> of the passage.

When the resilient valve <NUM> is in the first position, the fluid can move between the inner portion <NUM> of the resilient valve and the flow insert <NUM>, and into the second segment <NUM> of the passage. Thereafter, the fluid moves along the second segment <NUM> (Arrow A5) toward the proximal port <NUM>.

The resilient valve <NUM> is configured to respond to a change in pressure in the fluid flow path through the flow restriction device <NUM>. For example, the resilient valve <NUM>, or a portion thereof, can respond to a change in pressure in the fluid flow path by moving or biasing relative to other portions of the resilient valve or flow restriction device <NUM>. The change in pressure in the fluid flow path can exert a pressure on the resilient valve <NUM>, which causes the resilient valve <NUM> to bias or stretch.

When a suction pressure at the proximal port <NUM> exceeds a certain value or range, the inner portion <NUM> of the resilient valve is biased or stretches toward the flow insert <NUM> such that the resilient valve <NUM> is in the second position. The second position of the resilient valve <NUM> is illustrated in <FIG>.

In the second position, the resilient valve <NUM> has biased or stretched toward the flow insert <NUM> to resist or stop the flow rate of the fluid through the fluid flow path of the flow restriction device <NUM>. In some embodiments of the present disclosure, the shoulder <NUM> of the resilient valve is spaced apart from the valve seat <NUM> of the flow insert by a distance D2, where distance D2 is less than D1 when the resilient valve <NUM> is in the second position. In some embodiments of the present disclosure, the distance D2 is zero such that movement of a fluid through the flow restriction device <NUM> is resisted.

When the resilient valve <NUM> is in the second position, the flow rate of the fluid through the fluid flow path is reduced or stopped and the pressure on the fluid is thereby reduced. When the fluid moving through the fluid flow path is blood, the reduction of pressure can reduce homolysis to the blood.

In some embodiments of the present disclosure, the resilient valve <NUM> moves from the first position toward the second position when a pressure along the fluid flow path exerts a force of approximately <NUM> Newtons on the resilient valve <NUM>. In some embodiments, the resilient valve <NUM> is configured so that portion of the resilient valve, such as the inner portion <NUM>, is displaced or biased between approximately <NUM> to approximately <NUM> when a force of approximately <NUM> Newtons is exerted on the resilient valve <NUM>. In some embodiments, the resilient valve <NUM> is configured so that portion of the resilient valve, such as the inner portion <NUM>, is displaced or biased between approximately <NUM> to approximately <NUM> when a force of approximately <NUM> Newtons is exerted on the resilient valve <NUM>.

Claim 1:
A flow restriction device (<NUM>), comprising:
a flow insert (<NUM>) comprising a fluid passage extending therethrough, the fluid passage comprising a first segment (<NUM>) formed by an outer surface (<NUM>) of the flow insert, and a second segment (<NUM>) formed by an inner surface (<NUM>) of the flow insert;
a resilient valve (<NUM>) comprising a first end (<NUM>) engaged against the outer surface (<NUM>) of the flow insert, the first end (<NUM>) having an inner portion (<NUM>) aligned with the second segment (<NUM>) of the fluid passage, and an outer portion (<NUM>) aligned with the first segment (<NUM>) of the fluid passage, and an aperture (<NUM>) that extends through the resilient valve, from the first end (<NUM>) to a second end of the resilient valve;
wherein the inner portion (<NUM>) of the resilient valve is flexible, relative to the flow insert (<NUM>) such that in a first orientation of the resilient valve (<NUM>), the inner portion (<NUM>) is spaced apart from the flow insert by a first distance (D1) to permit a fluid to move from the first segment (<NUM>) toward the second segment (<NUM>) of the fluid passage, and in a second orientation of the resilient valve (<NUM>), the inner portion (<NUM>) is spaced apart from the flow insert (<NUM>) by a second distance (D2) to resist movement of the fluid between from the first segment (<NUM>) to the second segment (<NUM>) of the fluid passage.