Patent Description:
Many patient fluid transfer applications require a medical practitioner to take a sample of blood or fluid from the patient through an indwelling catheter. To that end, the practitioner typically uses a fluid transfer set having a sample port that allows the medical practitioner to draw a sample of the blood or fluid from the patient's indwelling catheter.

In some critical care applications, the medical practitioner may regularly monitor the patient's arterial or venous blood pressure through the fluid transfer set. In such applications, the fluid transfer set can include a pressure transducer that connects to a display that graphically shows a read-out of the arterial or venous blood pressure. Undesirably, the sampling ports of prior art fluid transfer sets can negatively interfere with the pressure transducer, causing erroneous blood pressure read-outs.

Conventional devices are known from <CIT>and <CIT>.

The invention is defined by the subject-matter of independent claims <NUM> and <NUM>. Further embodiments are defined in the respective dependent claims.

In accordance with one embodiment of the invention, a medical valve has an open mode that permits fluid flow, and a closed mode that prevents fluid flow. The valve is configured to be used in-line and in fluid communication with a pressure transducer. Accordingly, the valve has a housing with a housing wall, an inlet and an outlet. The housing has an interior contact surface at and/or between the inlet and/or the outlet. A resilient valve element sits within the housing interior and is configured to control fluid flow through the inlet. The resilient valve element has a body including a proximal portion that forms a normally closed aperture configured to open when actuated by a medical device. The resilient valve element also has a distal portion adjacent to the outlet, and a central portion between the proximal portion and the distal portion. The central portion of the resilient valve element has a wall with an interior surface that defines a fluid chamber in the open mode and in the closed mode. The wall has a plurality of gland projections extending radially outwardly. The gland projections and the contact surface of the housing are configured to maintain compressive contact to apply a radially inwardly compressive force on the resilient valve element when the valve is in the closed mode, thereby increasing the stiffness of the wall to reduce waveform distortion, as measured by the pressure transducer. The plurality of gland projections on the wall being spaced apart in a circular array around the central axis to form an interrupted ring, the interrupted ring forming interstices between gland projections, the housing wall having ribs, on an inner surface of the housing wall, that correspond to the interstices. At least one of the plurality of gland projections is distal of the normally closed aperture.

In accordance with yet another embodiment, a method reduces and/or removes artifacts from a pressure-waveform reading taken from a pressure transducer that is in-line with a medical valve. The medical valve has an open mode that permits fluid flow, and a closed mode that prevents fluid flow. The method provides a pressure transducer in-line and in fluid communication with a valve including a housing having a housing wall, an inlet and an outlet. The housing has an interior contact surface at and/or between the inlet and/or the outlet. The valve also has a resilient valve element within the housing interior that is configured to control fluid flow through the inlet. To that end, the resilient valve element has a body with a proximal portion having a normally closed aperture configured to open when actuated by a medical device, a distal portion adjacent to the outlet, and a central portion between the proximal portion and the distal portion. The central portion has a wall with an interior surface that defines a fluid chamber in the open mode and in the closed mode. The wall also has a plurality of gland projections extending radially outwardly. When the valve is in the closed mode, the method compressively contacts the gland projection with the contact surface of the housing so as to apply a radially inwardly compressive force on the resilient valve element, thereby increasing the stiffness of the wall to reduce waveform distortion as measured by the pressure transducer, the plurality of gland projections on the wall being spaced apart in a circular array around the central axis to form an interrupted ring, the interrupted ring forming interstices between gland projections, the housing wall having ribs, on an inner surface of the housing wall, that correspond to the interstices. The method then displays the pressure waveform reading.

Those skilled in the art should more fully appreciate advantages of various embodiments of the invention from the following "Description of Illustrative Embodiments," discussed with reference to the drawings summarized immediately below.

Undesirably, some prior art medical ports distort pressure waveform measurements from in-line transducers. In illustrative embodiments, a gland (also referred to as a resilient valve element) has one or more projections on its surface that are configured to radially support the gland, consequently reducing distortions in blood pressure measurements. Specifically, the inner diameter/surface of a valve housing compresses the projections, radially inwardly compressing the gland. The radially inward compression stiffens the gland, reduces waveform distortion, and ultimately provides better pressure waveforms measurements, for example, from an in-line pressure transducer. Details of illustrative embodiments are discussed below.

<FIG> schematically shows use of a medical valve in-line (also referred to as "valve <NUM>") with a pressure transducer in accordance with illustrative embodiments of the invention. As shown, the medical valve <NUM> may be connected to sections of tubing <NUM> and <NUM> extending between a patient <NUM> and a fluid bag <NUM> (e.g., on a fluid bag stand). Among other things, that tubing <NUM> and <NUM> may couple with the valve <NUM> by bonding, welding, press-fit, etc..

In some applications (e.g., in critical care applications), the medical practitioner <NUM> (e.g., a nurse <NUM>) may need to monitor venous or arterial pressure of the patient <NUM> (e.g., the intra-venous or intra-arterial blood pressure). Therefore, in some instances, the fluid transfer set may also include a pressure transducer <NUM> (i.e., a sensor) with a strain gauge that measures the pressure waveform within the artery or vein. The pressure is converted to an electrical signal that ultimately is forwarded to a monitor <NUM>. The monitor <NUM>, in turn, may display a graphic <NUM> representing the intra-arterial or intra-venous blood pressure waveform of the patient <NUM>. A healthcare provider, such as the nurse <NUM>, then may check the patient's <NUM> blood pressure waveform as a means to assess the status of the patient <NUM>.

<FIG> schematically shows examples of a normal blood pressure waveform reading 80A and a distorted blood pressure waveform reading 80B. Although shown simultaneously in the figure, the monitor <NUM> generally displays only a single graphic <NUM> (also referred to as waveform <NUM>). The two different graphics 80A and 80B are shown on the same monitor <NUM> for purposes of this description. Thus, waveform <NUM> appears either as normal waveform 80A or as distorted waveform 80B, but not both simultaneously. The graphic <NUM> therefore effectively may be considered to be output by the transducer <NUM>, as described above.

The inventors discovered that normal blood pressure readings 80A undesirably may become the distorted blood pressure readings 80B when transducers <NUM> are in-line and in fluid communication with some medical ports. To mitigate that problem, illustrative embodiments have a gland <NUM> with at least one projection <NUM> configured to maintain compressive contact with an inner surface of a valve housing <NUM> to significantly mitigate waveform <NUM> distortion (e.g., the appearance of the waveform <NUM> as the distorted waveform 80B).

<FIG> schematically shows a cross-sectional view of an illustrative embodiment of the valve <NUM> of <FIG> in a closed mode. The valve <NUM> has the noted housing <NUM> formed by an inlet housing <NUM> coupled with an outlet housing <NUM>. These two housings <NUM> and <NUM> may be coupled by any of a variety of techniques, such as via ultrasonic welding and/or a snap-fit connection. The housing <NUM> forms an interior chamber that contains the above noted gland <NUM>, which normally closes (e.g., seals) an opening <NUM> of the inlet housing <NUM>. The valve <NUM> is considered to be in the closed mode when the opening <NUM> is sealed. It should be further understood that although illustrative embodiments describe a closed mode that prevents fluid flow, the closed mode may only significantly mitigate fluid flow.

In accordance with preferred embodiments, the gland <NUM> (also referred to as a resilient valve element <NUM>) has a body that forms a lumen <NUM>, and a radially outwardly extending projection <NUM> that mitigates the prior noted signal distortion. Specifically, as described previously, the in-line transducer <NUM> may take a pressure measurement via a first fluid channel <NUM> connected to the tubing <NUM>. When pressure measurements are taken, the valve <NUM> is generally in the closed mode shown in <FIG>. As discussed in greater detail below, the projection <NUM> cooperates with the interior chamber to produce a more accurate waveform, such as waveform 80A of <FIG>.

The housing <NUM> also includes a proximal portion <NUM> and a valve wall <NUM> that extends distally from the proximal portion <NUM>. As shown in <FIG>, the valve wall <NUM> has an interior contact surface <NUM> that cooperates with the projection <NUM>. The gland <NUM> also has a distal portion <NUM> that preferably is open to form a distal port <NUM> in, or proximate to, the inlet housing <NUM>. To help support the gland <NUM>, the outlet housing <NUM> has an annular wall <NUM> that contacts the distal portion <NUM> of the gland <NUM>. As discussed in greater detail below, fluid (e.g., medication, saline, blood, etc.) flows through the lumen <NUM> of the valve <NUM> via the distal port <NUM> of the gland <NUM>.

The gland <NUM> thus may be considered to have a body with a proximal portion <NUM>, the noted distal portion <NUM>, and a central portion <NUM> (as shown in <FIG>) between the proximal and distal portions <NUM> and <NUM>. In some embodiments, the proximal portion <NUM> of the gland <NUM> is generally flush with the proximal portion <NUM> of the housing <NUM>. The proximal portion <NUM> of the gland <NUM> and the proximal portion <NUM> of the housing <NUM> thus present a swabbable surface, i.e., it may be easily wiped clean with an alcohol swab, for example, or other swab.

The opening <NUM> preferably is compatible with a luer taper and is configured to allow the medical practitioner <NUM> to draw a sample from the valve <NUM> interior. To that end, the gland <NUM> includes a resealable aperture <NUM> extending through at least a part of the proximal portion <NUM>. Among other things, the aperture <NUM> may be a pierced hole or a slit. Alternatively, the proximal portion <NUM> may be molded with the aperture <NUM>. When the gland <NUM> is in the closed mode (i.e., preventing passage of fluid), as shown in <FIG>, the aperture <NUM> may be held closed by radially inwardly directed pressure of the inner surface of the opening <NUM>. In that case, the inner diameter of the opening <NUM> may be smaller than the outer diameter of the proximal portion <NUM> and thus, squeezes the aperture <NUM> closed. Alternatively, the gland <NUM> (e.g., the proximal portion <NUM>) may be formed so that the aperture <NUM> normally stays closed in the absence of radially inward force provided by the inner diameter of the opening <NUM>. In other words, the proximal portion <NUM> may be formed so that the aperture <NUM> normally is closed.

<FIG> schematically shows a cross-sectional view of the valve <NUM> of <FIG> in the open mode in accordance with illustrative embodiments of the invention. During operation (e.g., when taking a sample from the valve <NUM>), the medical practitioner <NUM> may insert the medical implement <NUM> (e.g., a syringe) into the opening <NUM> of the housing <NUM>. As the medical implement <NUM> is inserted, the gland <NUM>, which normally closes the opening <NUM>, moves/deforms distally within the housing <NUM>. As the gland <NUM> continues to move/deform distally into the housing <NUM>, the aperture <NUM> opens (e.g., when the proximal portion <NUM> of the gland <NUM> enters the larger inner diameter portion of the proximal portion <NUM> of the housing <NUM>) to create fluid communication between the medical implement <NUM> and the lumen <NUM>. Conversely, when the medical implement <NUM> is withdrawn from the opening <NUM> (e.g., after sampling is complete), the elastomeric properties of the gland <NUM> cause the gland <NUM> to begin to move proximally within the housing <NUM> and return to its at-rest position with the proximal portion <NUM> within (and closing) the opening <NUM>.

The valve <NUM> has a plurality of fluid channels extending through the housing <NUM> that allow <NUM>) fluid to flow through the valve <NUM> and <NUM>) the sample to be taken through the opening <NUM>. For example, the housing <NUM> may form a second fluid channel <NUM> that effectively is the mirror image of the first fluid channel <NUM>. The first fluid channel <NUM> fluidly connects the lumen <NUM> with the tubing <NUM>, while the second fluid channel <NUM> fluidly connects the lumen <NUM> and the other tubing <NUM> (see <FIG>). As shown, both fluid channels in this embodiment have a larger horizontal portion and a smaller vertical portion (from the perspective of the figures). In this manner, when primed, fluid flows through the first fluid channel <NUM>, into the lumen <NUM>, and out of the valve <NUM> through the second fluid channel <NUM> and tubing <NUM>. Similarly, fluid may flow through the plurality of fluid channels of the sampling port <NUM> in the opposite direction.

As noted above, absent the projections <NUM>, the inventors discovered that pressure readings from the transducer taken in-line with the valve <NUM> become distorted (e.g., dampened). The inventors deduce that this distortion principally occurs as a result of movement by the unsupported body of the gland <NUM> (e.g., the central portion <NUM>) in response to pressure within the lumen <NUM>, due in part to the relatively large surface area within the lumen <NUM>. Illustrative embodiments compensate for the distortion in the waveform <NUM> measurement by providing the noted projections <NUM> on the outside surface of the gland <NUM>. In some embodiments, when in the closed mode, these projections <NUM> abut the inner surface of the inlet housing <NUM> and increase inward radial compression around a significant circumferential portion of the gland <NUM> (compared to gland compression when not within the inlet housing <NUM>). The inventors recognized that this gland stiffening/reinforcement across a rather large surface area improves the fidelity of the output waveform <NUM>-preferably causing it to look closer to waveform 80A of <FIG>.

As contrast, <FIG> schematically shows a perspective view of the gland <NUM> of <FIG> in an unconstrained state in accordance with illustrative embodiments of the invention. The gland <NUM> may be considered to have a central axis <NUM> running longitudinally through the proximal portion <NUM>, a central portion <NUM>, and the distal portion <NUM>. In the unconstrained state, no portion (<NUM>, <NUM>, or <NUM>) of the gland <NUM> is compressed (e.g., the gland <NUM> is not in the housing <NUM>).

The central portion <NUM> of the gland <NUM> includes a wall <NUM> having at least one projection <NUM> thereon. Illustrative embodiments may refer to a plurality of projections <NUM>, but it should be understood that the various embodiments described with reference to a plurality of projections <NUM> also apply to a singular projection <NUM>, and vice-versa. In some embodiments, each projection <NUM> may be shaped, for example, as a strip, such as a full ring, and/or a tab/flap of material. The projections <NUM> may be formed from the same material as the gland <NUM>, a different material, or from a combination of materials. For example, the projections <NUM> may be overmolded from a stiffer durometer material using a two-shot molding process. Furthermore, the projections <NUM> may be molded with the gland <NUM> or attached (e.g., using adhesive). Preferably, the projections <NUM> are of similar durometer or stiffer durometer than the gland <NUM> body itself, to help compress the gland <NUM> body. In illustrative embodiments, at least a portion of the projections <NUM> are concyclic on the wall <NUM>.

As noted above, the projections <NUM> are configured to come into, and maintain, compressive contact with the inner contact surface <NUM> of the housing <NUM> (e.g., the inner surface of the valve wall <NUM>, see <FIG>) when the gland <NUM> is in the housing <NUM>. Some embodiments may tune the projections <NUM> to provide varying amounts of compressive contact. To that end, illustrative embodiments of the projections <NUM> may have variable thickness <NUM> (measured along the central axis <NUM>), height <NUM> (e.g., distance from the wall <NUM> measured transverse to the central axis <NUM>), and width/arc <NUM> configured to provide various amounts of compressive contact with the contact surface <NUM>. The dimensions (e.g., circumference) of the contact surface <NUM> also factor into the amount of radial compression on the gland <NUM>. In illustrative embodiments, the projections <NUM> may contact the contact surface <NUM> in the open mode and in the closed mode. Furthermore, the projections <NUM> may have compressive contact with the contact surface <NUM> in the open mode and/or in the closed mode.

The compressive contact on the projections <NUM> provides the noted stiffening, inward radial compression on the gland <NUM>. Generally, compressing the gland <NUM> with projections <NUM> on opposite sides (e.g., <NUM> degree separation) provides compressive contact. However, it should be understood that a variety of different projection <NUM> locations and contact surface <NUM> areas are sufficient to provide compressive contact. Compressive contact (e.g., at the central portion <NUM>) stiffens the gland <NUM> and reduces distortion in the pressure wave readings. Compressive contact may cause compression of the height <NUM> of the projection <NUM> and/or in the outer diameter of the wall <NUM>. Additionally, compressing the height <NUM> may increase the thickness <NUM> of the projection <NUM>. For example, interference between the outer diameter <NUM> of the projection <NUM> and the inner diameter <NUM> of the contact surface <NUM> causes compressive contact (see <FIG>). The gland <NUM> is compressed radially inwardly as a result of the interference. A single projection <NUM> and/or a plurality of projections <NUM> may have, but do not require, a uniform height <NUM>. Furthermore, illustrative embodiments may have, but do not require, that the projections <NUM> are offset by <NUM> degrees.

<FIG> schematically shows a gland of the prior art that is uncompressed by the inner diameter of the housing. <FIG> schematically show cross-sectional views of various embodiments of the gland <NUM> within the housing <NUM>, in accordance with illustrative embodiments of the invention. <FIG> schematically shows a prior art gland without any projections. <FIG> schematically show the gland wall <NUM> having projections <NUM> that are in translational contact (i.e., the wall <NUM> is not squeezed by the contact) with the housing <NUM>.

Compressive contact is distinguishable from translational contact. In some embodiments, the projections <NUM> on the gland wall <NUM> form a larger outer diameter than the inner diameter of the contact surface <NUM>. To some small degree, all contact can be said to provide some amount of compression. However, translational contact pushes the gland <NUM> more than it compresses (e.g., squeezes and/or stiffens) the gland <NUM>. Furthermore, translational contact may provide a single point of contact that directs force inwardly, but it does not provide radially inward compression (except, for example, when the gland <NUM> is pushed sufficiently to cause it to press against an opposing contact surface <NUM> as shown for example in <FIG>). However, while illustrative embodiments of the gland wall <NUM> may be compressed between the projection <NUM> and the contact surface <NUM> (as shown in <FIG>), practically it may be difficult or impossible to insert a luer effectively (e.g., transition from the closed mode to the open mode in a hospital setting is difficult because opening of gland <NUM> may be offset from the longitudinal axis <NUM> and the gland body may be warped). In such an instance, the gland <NUM> cannot be said to be configured to readily open when actuated by a medical implement <NUM>.

<FIG> schematically shows embodiments where the projections <NUM> provide radially inward compression on the gland wall <NUM>. As shown in <FIG>, illustrative embodiments have three or more projections <NUM> on the surface of the wall <NUM>, that are spread equidistantly around the surface of the wall <NUM>. For example, the center of projections <NUM> may be separated about approximately <NUM> degrees on the surface of the gland wall <NUM>. As shown in <FIG>, illustrative embodiments may have projections <NUM> whose centers are separated by approximately <NUM> degrees on the surface of the gland wall <NUM>.

Furthermore, in some embodiments, the projections <NUM> may contact between about <NUM> degrees and about <NUM> degrees of the circumference of the gland wall <NUM>. Alternatively, as shown in <FIG>, in some embodiments the projections <NUM> may contact between about <NUM> degrees and about <NUM> degrees of the circumference of the gland wall <NUM>. Some embodiments may cover more than <NUM> degrees of the circumference gland wall <NUM> (e.g., <NUM> degrees as shown by the full ring projection <NUM> in <FIG>). It should be understood that generally, the more total contact surface area <NUM> (e.g., as a result of thickness <NUM> and arc length <NUM>) the less radial interference (e.g., as a result of height <NUM>) required to stiff the gland wall <NUM> and reduce waveform distortion. In some embodiments, compressing the thickness of the gland wall <NUM> by at least <NUM>% is sufficient to reduce waveform <NUM> distortion (e.g., if the gland wall <NUM> is <NUM> thick, compressing the thickness by at least <NUM>). Additionally, some embodiments may compress the thickness of the gland wall <NUM> by at least <NUM>%, <NUM>%, or more. Alternatively, some embodiments may compress the gland wall <NUM> by less than <NUM>% (e.g., between <NUM>% and <NUM>%).

Projections <NUM>, and/or portions (e.g., portions <NUM> and <NUM>) thereof, may be configured to have variable heights <NUM>, thicknesses <NUM>, and arc lengths/widths <NUM>. As is known in the art, the arc length <NUM> is calculated by the radius of the arc (e.g., the distance from the central axis <NUM>) multiplied by the angle θ. Adjusting these parameters provides different amounts of inwardly radial compression on the gland <NUM> when the contact surface <NUM> compresses the projection <NUM>. In addition, varying these parameters alters the force required by the medical practitioner <NUM> to insert the medical implement <NUM> into the opening <NUM> of the housing <NUM> and to move/deform the gland <NUM> (as will be described in further detail below). Preferably, a portion of the projection <NUM> freely deforms within the interior chamber of the housing <NUM> as the valve transitions from the closed mode to the open mode.

Furthermore, illustrative embodiments show the gland projections <NUM> contacting the inlet contact surface <NUM> in the closed mode and in the open mode. Preferably, the projection <NUM> contacts the same surface <NUM> when in the closed mode and in the open mode. For example, the projection <NUM> may "slide" along the surface <NUM> to reduce the amount of resistive force required to move the gland from the closed mode to the open mode. In some embodiments, however, the gland projections <NUM> may contact the contact surface <NUM> (e.g., inlet contact surface <NUM>) only in the closed mode.

<FIG> shows a single projection <NUM> formed as a non-uniform ring <NUM>. The non-uniform ring <NUM> has thicker portions <NUM> (e.g., compression tabs <NUM>) interspersed with thinner portions <NUM> (e.g., compression strips <NUM>). The portions <NUM> and <NUM> have different heights <NUM>, thicknesses <NUM>, and arc lengths/widths <NUM>. However, both of the portions <NUM> and <NUM> are part of a single, integrated projection <NUM>. Although <FIG> shows a single projection <NUM> on the central portion <NUM>, it should be understood that illustrative embodiments may have more than one projection <NUM> on the central portion <NUM>. Additionally, or alternatively, illustrative embodiments may have at least one projection <NUM> on one or more of the proximal portion <NUM>, the distal portion <NUM>, and the central portion <NUM>.

<FIG> schematically shows a perspective view of the gland <NUM> of <FIG> in a constrained/compressed state (e.g., in the closed mode), in accordance with illustrative embodiments of the invention. In the constrained state, the gland <NUM> is within the housing <NUM> (not shown for visibility of the gland <NUM>) and the contact surface compresses the projections <NUM>. As shown in the figure, both the thicker portions <NUM> and the thinner portions <NUM> are compressed (e.g., their height <NUM> has decreased and their shape has changed). In some embodiments, the thickness <NUM> and/or width <NUM> may deform to compensate for the compression over the height <NUM>. Although both portions <NUM> and <NUM> of the projection <NUM> are compressed, illustrative embodiments do not require that the entirety of the projection <NUM> be compressed. Compressive contact with a portion (e.g., <NUM> or <NUM>) of one or more projections <NUM> may cause sufficient inward radial compression. For example, <NUM> degree opposite sides of the gland <NUM> may have projections <NUM> that are compressed.

In some embodiments, the projection <NUM> (e.g., portions <NUM> and <NUM>) may be configured to have a total projection contact surface area <NUM>. The projection contact surface area <NUM> is the portion of the projection <NUM> that is physically in contact with the contact surface <NUM> of the housing <NUM> in the closed mode. For comparison, <FIG> shows a projection non-contact surface area <NUM>. As shown, the non-contact surface area <NUM> is not directly in contact with the contact surface <NUM> of the housing <NUM> and may freely deform within the interior chamber of the housing <NUM> as the valve <NUM> transitions from the closed mode to the open mode.

Illustrative embodiments may have projections <NUM> shaped as a non-uniform ring <NUM> to reduce, relative to a uniform ring <NUM>, the resistive forces on the medical implement <NUM> when it is inserted into the valve <NUM> (e.g., when the valve transitions from the closed mode shown in <FIG> to the open mode shown in <FIG>). The non-uniform ring <NUM> eases movement of the projection <NUM> relative to the main body of the gland <NUM>. The ring <NUM> also provides a reduction in contact area with the contact surface <NUM> that allows the projection <NUM> to more easily deform against the contact surface <NUM> when the medical implement <NUM> is inserted. Thus, the force that may otherwise be required to insert the medical implement <NUM> into the valve <NUM> is reduced.

<FIG> schematically shows an alternative embodiment of the gland <NUM> in accordance with illustrative embodiments of the invention. The gland <NUM> may have one more uniform ring projections <NUM>. The projection <NUM>, similar to the projection <NUM> in <FIG>, has a thickness <NUM> and a height <NUM>. However, the projection <NUM> has a <NUM> degree arc length <NUM>. When the gland <NUM> is placed within the housing <NUM>, the projection <NUM> is compressed along <NUM> degrees of angular contact. It should be understood that just because the projection <NUM> is compressed along <NUM> degrees of angular contact, does not necessarily mean that the gland <NUM> experiences more inward radial compression than illustrative embodiments that are not compressed a full <NUM> degrees. The magnitude of compression is based on the dimensions of the projection <NUM> (e.g., surface area, height <NUM>, thickness <NUM>, arc length <NUM>), the dimensions of the housing <NUM> (e.g., contact surface <NUM>), and the interference between the projection <NUM> and the housing <NUM> (including the amount of angular contact). Those skilled in the art may select those parameters to achieve a desired compression for a given application.

Illustrative embodiments having the <NUM> degree uniform ring projection <NUM> undesirably may provide more resistance when inserting the medical implement <NUM> than is desirable. To mitigate this problem, illustrative embodiments have a nonuninform projection <NUM> (shown in <FIG>), or break the single projection <NUM> into a plurality of projections <NUM> (e.g., an interrupted ring projection <NUM> - shown in <FIG>).

<FIG> schematically shows a cross-sectional view of the gland <NUM> of <FIG> constrained within its valve <NUM>. As with other embodiments, the contact surface <NUM> compresses the gland <NUM> radially inwardly by compressively contacting the projection <NUM> via interference between the outer diameter <NUM> of the projection <NUM> and the inner diameter <NUM> of the contact surface <NUM>. For example, gland body outer diameter <NUM> when uncompressed may be <NUM> inches, the ring projection <NUM> may have an uncompressed outer diameter <NUM> of <NUM> inches, and the inner diameter <NUM> of the inlet contact surface <NUM> may be <NUM> inches. In some embodiments, the projection <NUM> may be, but is not required to be, formed from a harder durometer material than the gland <NUM> body, and thus, the gland <NUM> body may experience radially inward compression. For example, the outer diameter <NUM> may be compressed about. <NUM> inches. Alternatively, the projection <NUM> may be formed from a similar or lower durometer material as the gland <NUM>, and may, for example, experience a similar compression of about. <NUM> inches. For example, it may be easier to insert a medical implement <NUM> into the gland <NUM> (e.g., to facilitate translation from the closed mode to the open mode) if the projection <NUM> is made of a lower durometer material. The above described dimensions are merely exemplary and not intended to limit illustrative embodiments of the invention. Furthermore, based on the materials of the gland <NUM>, the projection <NUM>, and the housing <NUM>, all of the components may experience a change in their dimensions (e.g., the projection <NUM> may compress, the gland <NUM> body may compress, and/or the inlet housing <NUM> may expand albeit minutely on a relative basis).

In some embodiments, the gland body outer diameter <NUM> may be compressed between about. <NUM> inches and about. <NUM> inches. More specifically, the gland body outer diameter <NUM> may be compressed about. <NUM> inches and about. <NUM> inches. In some embodiments, the amount of diametric interference between the projection <NUM> (e.g., ring projection <NUM>) and inlet inner diameter <NUM> is less than. <NUM> inches per side (. <NUM> inches per diameter). It should be understood that the more contact surface area <NUM> the projection <NUM> has (e.g., thickness <NUM>) the less diametric interference required to effectively stiffen the gland <NUM>. A larger contact surface area <NUM> for the projection <NUM> is preferred, as the larger contact surface area <NUM> requires less diametric inward compression to stiffen the gland <NUM>. That large contact surface area <NUM> should be balanced against frictional resistance between the gland and the inlet housing <NUM> when inserting and removing the medical implement <NUM>, as well as the ability of the projection <NUM> to freely deform within the interior chamber of the housing <NUM>.

In <FIG>, the outer diameter <NUM> of the projection <NUM> is shown as overlapping the inner diameter <NUM> of the inlet housing <NUM> and the contact surface <NUM>. However, this is merely to illustrate interference between the outer diameter <NUM> and the inner diameter <NUM>. It should be understood that in actuality, the gland <NUM> is compressed by the valve wall <NUM> and the outer diameter of the projection <NUM> does not extend into the valve wall <NUM>.

<FIG> schematically shows yet another alternative embodiment of the gland <NUM> in accordance with illustrative embodiments. As shown in the figure, the projections <NUM> form a plurality of interrupted rings. For example, projections 110A, 110F, and the other projections <NUM> coplanar along the central axis <NUM> form a first ring. Projection 110A and 110F are spaced radially with respect to the central axis <NUM>. Projection 110B and the other projections <NUM> spaced radially along the central axis <NUM> form a second ring.

Illustrative embodiments may contain a plurality of different projections 110A-110E that are shaped differently. Although all of the projections 110A-110E have the same height <NUM> and widths <NUM>, they have varying thicknesses <NUM>. Illustrative embodiments may have projections <NUM> of varying heights <NUM>, widths <NUM> and/or thicknesses <NUM>. Furthermore, illustrative embodiments may be spaced along the central axis <NUM> with varying intervals. For example, projection 110E is spaced further away from projection 110D with respect to the central axis <NUM> than projection 110B is spaced from projection 110C. A radial interstice <NUM> (e.g., a space) is formed between radially spaced apart projections (e.g., 110A and 110F). A longitudinal interstice <NUM> is formed between projections <NUM> spaced apart along the central axis <NUM> (e.g., 110A and 110B).

As described earlier, rather than a single thick ring for the projection <NUM>, some embodiments use a plurality of projections <NUM> to reduce frictional resistance to longitudinal gland <NUM> movement, enabling the gland <NUM> more free longitudinal movement in use. Furthermore, projections having a thickness <NUM> that is smaller than the height <NUM> are more prone to bending during longitudinal movement of the gland <NUM>, thus, offering the potential for less resistance when inserting the medical implement <NUM>. To that end, in some embodiments, the height <NUM> may be larger than the thickness <NUM>. Alternatively, in some embodiments, the thickness <NUM> may be larger than the width <NUM>. Furthermore, in some embodiments, the projections <NUM> may have reduced attachment surface area with the gland wall <NUM>. For example, projection 110A has a beveled <NUM> attachment surface. Additionally, or alternatively, some projections 110E may be formed from thin pieces of material. Although the figure shows the interstices <NUM> and <NUM> aligned in columns and rows, it should be understood that the interstices <NUM> and <NUM> and are not required to be aligned. For example, projections <NUM> may overlap with interstices along the central axis <NUM> or radially. Furthermore, projections <NUM> are not required to be aligned in columns and/or rows.

<FIG> schematically shows the gland <NUM> of <FIG> used with an alternative embodiment of the housing <NUM> in accordance with illustrative embodiments of the invention. The inlet housing <NUM> and/or the outlet housing <NUM> may have housing projections <NUM> on their inner surfaces that are directed radially inwardly. In some embodiments, the housing projections <NUM> may be formed as ribs. Furthermore, the housing projections <NUM> may be configured to align with the radial interstices <NUM> and/or longitudinal interstices <NUM>. It should be understood that radial interstices <NUM> are called "radial" because they are formed between radially spaced projections <NUM>. In a similar manner, longitudinal interstices <NUM> are "longitudinal" because they are formed between longitudinally spaced projections <NUM>. Alternatively, some embodiments may have housing projections <NUM> without any gland projections <NUM>. It should be understood that although illustrative embodiments are shown as having housing projections <NUM> on the inlet housing <NUM>, the housing projections <NUM> additionally, or alternatively, may be on the outlet housing <NUM>.

<FIG> schematically shows an alternative embodiment of the gland <NUM> in accordance with illustrative embodiments of the invention. The projection <NUM> may have a small point of attachment <NUM> relative to its thickness <NUM>. The remainder of the space between the projection <NUM> and the gland wall <NUM> may form a slip plane <NUM> that allows the projection <NUM> to move freely relative to the body of the gland <NUM> when a medical implement <NUM> is inserted. The slip plane <NUM> reduces the amount of force required to insert the medical implement <NUM> into the valve <NUM>. Illustrative embodiments may have multiple projections <NUM> offset radially and/or longitudinally, and one or more of the projections <NUM> may have slip planes <NUM>.

<FIG> schematically shows a distal perspective view of an alternative embodiment of the gland <NUM> having internal ribs <NUM>, in accordance with illustrative embodiments of the invention. The internal ribs <NUM> help maintain the integrity of the gland <NUM> by adding thickness to the gland wall <NUM>. As with other embodiments, the plurality of radial interstices <NUM> are formed between radially spaced projections <NUM>. As shown, the projections <NUM> may extend substantially along the entire length of the central portion <NUM>. Furthermore, the gland <NUM> may have distal projections <NUM> on the distal portion <NUM>.

To reinforce the thickness of the wall <NUM>, internal ribs <NUM> may be formed on the inner surface <NUM> of the gland wall <NUM>. The internal ribs <NUM> may assist with uniformity of deformation when the medical implement <NUM> is inserted. In illustrative embodiments, the ribs <NUM> may be aligned <NUM> with the interstices <NUM> and/or <NUM>. The ribs <NUM> as shown align with the radial interstices <NUM>. Additionally, or alternatively, the ribs <NUM> may align with the longitudinal interstices <NUM> (not shown).

In some embodiments, one or more projections <NUM> may be on any of the proximal portion <NUM>, the central portion <NUM>, and/or the distal portion <NUM>. Furthermore, to aid with stiffening the gland, the proximal portion <NUM> and/or the distal portion <NUM> may be constrained by the housing <NUM>.

In some embodiments, the projection <NUM> may be part of the gland <NUM> (e.g., molded with or attached via adhesive), a separate piece, or may be part of the inner diameter <NUM> of the valve <NUM>.

<FIG> shows a process of measuring the blood pressure waveform <NUM>, in accordance with illustrative embodiments of the invention. It should be noted that this process may be, in some instances, substantially simplified from a longer process of measuring a pressure waveform <NUM>. Accordingly, the process of measuring a waveform <NUM> typically has other steps that those skilled in the art likely also would use. In addition, some of the steps may be performed in a different order than that shown, or at the same time. Those skilled in the art therefore can modify the process as appropriate.

The process of <FIG> begins at step <NUM>, in which the gland <NUM> having projections <NUM> is provided. As described previously, the projections <NUM> may take many forms, such as a complete ring, a non-uniform ring, an interrupted ring, and/or combinations thereof. Furthermore, the projections <NUM> may cover at least along <NUM> degrees of the circumference of the gland <NUM>. It should be understood that the term "cover," as used in this application, does not necessarily mean the projection <NUM> spans the entire length of the central portion <NUM>. Instead, the term "cover" is used to refer to the angle of radial coverage (out of <NUM> degrees) around the gland wall <NUM>. Thus, two opposing projections <NUM> with an arc length of <NUM> degrees, even if they are offset along longitudinally (e.g., in a direction along the central axis <NUM> of the gland <NUM>) may be said to cover <NUM> degrees of the wall <NUM>. However, in some embodiments, all of the coverage values described in this application may be concyclic, i.e., the projections <NUM> are formed on a common circle around the gland wall <NUM>. Illustrative embodiments above describe details of the projections <NUM>.

The process then positions the gland <NUM> within the valve housing <NUM> at step <NUM>. In some embodiments, a medical practitioner <NUM> may position the gland <NUM> within the valve housing <NUM>. In preferred embodiments, the manufacturer positions the gland <NUM> within the housing <NUM>, and sterilizes the valve <NUM> at that time, prior to packaging and shipping. When the valve <NUM> is positioned inside the housing <NUM>, the projections <NUM> are compressed radially inwardly by the contact surface <NUM> of the housing <NUM>. This compressive contact stiffens the gland <NUM>.

Next, at step <NUM>, the valve <NUM> is used with the patient <NUM>, preferably in line with a pressure transducer <NUM>. The medical practitioner <NUM> may set up the valve <NUM> and/or the pressure transducer <NUM>. When the valve <NUM> is in the closed mode, a pressure waveform reading <NUM> may be taken, as described with reference to <FIG>.

Next, at step <NUM>, a pressure waveform measurement <NUM> may be taken. Because the gland <NUM> was stiffened in step <NUM>, artifacts that may otherwise appear in the pressure waveform measurement 80A are reduced. Accordingly, the medical practitioner <NUM> has access to more accurate pressure waveform measurements 80A and may provide better medical care.

Claim 1:
A medical valve (<NUM>) having an open mode that permits fluid flow, and a closed mode that prevents fluid flow, the medical valve (<NUM>) configured to be used in-line and in fluid communication with a pressure transducer (<NUM>), the medical valve (<NUM>) comprising:
a housing (<NUM>) having a housing wall, an inlet and an outlet, the housing (<NUM>) having an interior contact surface (<NUM>) at and/or between the inlet and/or the outlet;
a resilient valve element (<NUM>) within the housing interior configured to control fluid flow through the inlet, the resilient valve element (<NUM>) having a body comprising:
a proximal portion (<NUM>) forming a normally closed aperture (<NUM>) configured to open when actuated by a medical device (<NUM>),
a distal portion (<NUM>), and
a central portion (<NUM>) between the proximal portion (<NUM>) and the distal portion (<NUM>), the central portion (<NUM>) having a wall (<NUM>) with an interior surface that defines a fluid chamber (<NUM>) in the open mode and in the closed mode,
the wall (<NUM>) having a plurality of gland projections (<NUM>) extending radially outwardly, at least one of the plurality of gland projections (<NUM>) and the contact surface (<NUM>) of the housing (<NUM>) configured to maintain compressive contact to apply a radially inwardly compressive force on the resilient valve element (<NUM>) when the valve (<NUM>) is in the closed mode and thereby increase the stiffness of the wall (<NUM>) to reduce waveform distortion as measured by the pressure transducer (<NUM>),
the plurality of gland projections (<NUM>) on the wall (<NUM>) being spaced apart in a circular array around the central axis (<NUM>) to form an interrupted ring, the interrupted ring forming interstices (<NUM>) between gland projections (<NUM>), the housing wall having ribs (<NUM>), on an inner surface of the housing wall, that correspond to the interstices (<NUM>),
at least one of the pluralities of gland projections (<NUM>) being distal of the normally closed aperture (<NUM>).