Pressure activated proximal valves

A medical device is disclosed comprising a diaphragm having at least one slit valve disposed therein, and a valve housing configured to secure the diaphragm at a peripheral portion of the diaphragm, wherein a central portion of the diaphragm is positioned relative to the peripheral portion of the diaphragm such that compressive forces acting on the peripheral portion of the diaphragm create moment forces which bias the slit valve in a closed position. A method is disclosed for using the device in connection with a catheter for regulation of fluids to and from a patient.

BACKGROUND

In medicine, an embolism occurs when an object (the embolus, plural emboli) migrates from one part of the body (through circulation) and causes a blockage of a blood vessel in another part of the body. Blood clots form a common embolic material. Other possible embolic materials include fat globules (a fat embolism), air bubbles (an air embolism), septic emboli (containing pus and bacteria), or amniotic fluid. Emboli often have more serious consequences when they occur in the so-called “end-circulation” areas of the body that have no redundant blood supply, such as the brain, heart, and lungs. Assuming normal circulation, a thrombus or other embolus formed in a systemic vein will always impact in the lungs, after passing through the right side of the heart. This forms a pulmonary embolism that can be a complication of deep-vein thrombosis.

Embolism can be contrasted with a “thrombus” which is the formation of a clot within a blood vessel, rather than being carried from elsewhere. Thrombus, or blood clot, is the final product of the blood coagulation step in hemostasis. It is achieved via the aggregation of platelets that form a platelet plug, and the activation of the humoral coagulation system (i.e., clotting factors). A thrombus is physiologic in cases of injury, but pathologic in case of thrombosis. A thrombus in a large blood vessel will decrease blood flow through that vessel. In a small blood vessel, blood flow may be completely cut-off resulting in the death of tissue supplied by that vessel. If a thrombus dislodges and becomes free-floating, it becomes an embolus.

Some of the conditions in which blood clots develop include atrial fibrillation (a form of cardiac arrhythmia), heart valve replacement, a recent heart attack, extended periods of inactivity (see deep venous thrombosis), and genetic or disease-related deficiencies in the blood's clotting abilities.

Preventing blood clots reduces the risk of stroke, heart attack and pulmonary embolism. Heparin and warfarin are often used to inhibit the formation and growth of existing blood clots, thereby allowing the body to shrink and dissolve the blood clots through normal methods (see anticoagulant). Regulating fluid flow through catheters can help minimize embolism and health risks associated therewith.

BRIEF SUMMARY

One aspect of the present invention discloses a medical device comprising a diaphragm having at least one slit valve disposed therein and at least one valve control member. The term “diaphragm,” as used herein, can be defined as any membranous part that divides or separates. The valve control member can be configured to cover at least a portion of the diaphragm without covering any portion of the slit valve and can be further configured to control deflection of the diaphragm. In another aspect of the invention, the valve control member comprises at least one arm extending from an outer portion of the valve control member to an inner portion of the valve control member. In still another aspect of the invention, the valve control member comprises a plurality of arms extending from an outer portion of the valve control member to a center portion of the valve control member. Further, the medical device can comprise a valve housing having the diaphragm therein, the valve housing being configured to be attached to an elongated tubular member, the elongated tubular member configured for at least partial placement into a portion of a patient. In another aspect of the invention, at least a portion of the slit valve has a nonlinear orientation. In another aspect of the invention the slit valve further comprises a plurality of interconnected linear slits oriented in different directions.

In another embodiment, a medical device for regulating fluid flow comprises a diaphragm having a slit valve disposed therein and a valve housing configured to secure the diaphragm at a peripheral portion of the diaphragm. A distal end of the valve housing can be further configured to attach to a proximal end of an elongated tubular member, such as a catheter. A central portion of the diaphragm is positioned relative to the peripheral portion of the diaphragm such that compressive forces acting on the peripheral portion of the diaphragm create moment forces which bias the slit valve in a neutral position. In one aspect of the invention, an outer portion of the diaphragm is thicker than an inner portion of the diaphragm. Alternatively, in another aspect of the invention, an outer portion of the diaphragm is thinner than an inner portion of the diaphragm. In still another aspect of the invention, the diaphragm may be substantially circular or substantially oval. In an additional embodiment of the invention, at least a portion of the diaphragm approximates the shape of a dome structure. In one aspect, the diaphragm further comprises a concave or convex annular member which circumscribes the dome structure. In one embodiment, the diaphragm is oriented substantially perpendicular to a direction of flow through the valve housing. In another embodiment, the diaphragm is oriented at an obtuse angle relative to a direction of flow through the valve housing. In one aspect, the diaphragm narrows from a lateral portion of the diaphragm to an opposite lateral portion of the diaphragm. In still another aspect, at least two slit valves are installed on opposing sides of the diaphragm.

In another embodiment, the diaphragm of the medical device further comprises at least one protruding member on a proximal end of the diaphragm configured to assist the slit valve to return to the biased neutral position. In one aspect, the diaphragm further comprises a pair of centrally located opposing protruding members on a proximal end of the diaphragm configured to assist the slit valve to return to the biased neutral position.

One embodiment of the invention contemplates a medical device comprising a diaphragm with at least one slit valve disposed therein. The proximal surface and distal surface of the diaphragm approximate a dome structure. The diaphragm is configured such that a portion of the proximal end of the diaphragm contiguous with the slit valve is thinner than an adjacent portion of the diaphragm. In one aspect, the diaphragm is secured at a peripheral portion by a valve housing, a distal end of the valve housing being configured to attach to a proximal portion of an elongated tubular member. In another aspect, the height of the peripheral portion of the diaphragm is greater than the height of the dome structure of the diaphragm at the apex of the dome structure of the diaphragm. In yet another aspect, the height of the peripheral portion of the diaphragm is approximately twice the width of the peripheral portion of the diaphragm. In another embodiment, the peripheral portion of the diaphragm is compressed by the valve housing approximately five to 15 percent. In another embodiment, a central portion of the diaphragm is subjected to moment forces from compression of the peripheral portion of the diaphragm thereby biasing the slit valve in a neutral position. In still another embodiment, a central portion of the diaphragm is positioned at a proximal end of the peripheral portion of the diaphragm.

In another embodiment of the present invention, a medical device comprises a cylindrical member having a proximal end configured to be secured at a peripheral portion by a valve housing, wherein the peripheral portion has a circumference greater than the circumference of the main cylindrical member. The medical device further comprises at least one slit valve placed on an outer wall of the cylindrical member. The slit valve is oriented parallel to a longitudinal axis of the cylindrical member. In one aspect, a distal end of the valve housing is configured to attach to a proximal end of an elongated tubular member, wherein a distal portion of the elongated tubular member is configured to be placed within a portion of a patient.

In a further embodiment, a medical device comprises a pressure-activated valve having an open circular proximal end and an at least partially closed distal end. The medical device is further configured such that the distal end comprises at least a partially planar surface having at least two slits oriented in different directions disposed therein. The slits have at least one common intersection and are configured to actuate in a distal direction in response to a first pressure differential. The medical device is further configured such that a portion of the distal end of the valve is defined by an interior angle of the intersecting slits, an outer portion of the distal end of the valve tapering from the distal end of the valve towards the proximal end of the valve thereby forming a channel on the outer portion of the distal end of the valve. In one aspect, the medical device further comprises at least one proximal-actuating slit valve installed on the distal end. The slit valve is configured to actuate in a proximal direction in response to a second pressure differential. In this aspect, the second pressure differential is greater than the first pressure differential. In another aspect, the slits placed in the distal end of the valve are oriented to approximate the shape of a cruciform thereby separating the distal end of the valve into quadrants. In one aspect, the valve is further configured such that the center of the cruciform is approximately collinear with the center of the circular proximal end of the valve. In yet another aspect, the at least one proximal-actuating slit valve is placed in a bottom portion of the channel.

In an additional embodiment, a method is disclosed comprising the steps of placing a distal end of a catheter into a vasculature of a patient, wherein a proximal end of the catheter has a medical device connected thereto. The medical device comprises a diaphragm having at least one slit valve disposed therein and a valve housing configured to secure the diaphragm at a peripheral portion of the diaphragm. A central portion of the diaphragm is positioned relative to the peripheral portion of the diaphragm such that compressive forces acting on the peripheral portion of the diaphragm create moment forces which bias the slit valve in a neutral position. The method further comprises the steps of creating a first liquid pressure differential across the slit valve thereby infusing liquids into the patient and creating a second pressure differential across the slit valve thereby aspirating liquids from a patient.

Features from any of the above-mentioned embodiments may be used in combination with one another in accordance with the instant disclosure. In addition, other features and advantages of the instant disclosure will become apparent to those of ordinary skill in the art through consideration of the ensuing description, the accompanying drawings, and the appended claims.

DETAILED DESCRIPTION

One aspect of the instant disclosure relates to apparatuses and systems for pressure-activated valves for use with a medical device. Specifically, the instant disclosure contemplates that a slit valve may be disposed within a medical device, such as a catheter, for selective infusion and aspiration of fluids through the catheter and into a patient.

Referring toFIG. 1, catheter assembly10may be of any type that can be disposed within a body cavity, duct, or vessel. Examples of such catheters include, without limitation, peripherally inserted central catheters, central venous catheters, intravenous catheters, urological catheters, as well as catheters utilized for ventilation, pleural drainage, angioplasty, or enteral feeding.FIG. 1illustrates a catheter14peripherally placed via a subclavian vein12. However, catheter14can be disposed within any portion of a patient wherein drainage, injection or aspiration of fluids, access by surgical instruments, etc. is desired. Catheter14comprises a first portion15having distal end20configured for placement into a portion of a patient25and a proximal end30configured for attachment to a valve assembly35. Catheter assembly10further comprises a second portion40having a distal end41configured for attachment to valve assembly35and a proximal end42configured for attachment to a fluid source43and a fluid removal and fluid injection location44.

In one embodiment, fluid may be delivered via catheter assembly10to patient25via an IV bag connected to a proximal portion of the catheter assembly10wherein the fluid is substantially gravity-fed to the patient25. In another embodiment, fluids may be power injected via the catheter assembly10to the patient25by connecting a proximal portion of the second portion40of the catheter assembly10to a power injection system. In another aspect of the invention, fluids may be aspirated by connecting a syringe to the fluid removal location44and applying negative pressure to the catheter assembly10.

Generally, one aspect of the invention contemplates a pressure-activated valve positioned in the flow path of a catheter inserted into a patient. The valve can be actuated in a distal direction by a first pressure differential, for example, gravity-induced pressure from a fluid source, such as an IV bag. The valve can also be actuated in a distal direction, for example, by power injection of contrast media into the patient. The valve can also be actuated in a proximal direction by a second pressure differential, for example, by negative pressure from a syringe thereby enabling blood withdrawal from the patient. In one embodiment, the first pressure differential is less than the second pressure differential. However, any of the pressure-activated valves disclosed herein can be reversed thereby changing the pressure differential paradigm (e.g., the first pressure differential is greater than the second pressure differential).

Referring now toFIGS. 1 through 4, in one embodiment, a valve assembly35can include a diaphragm45with at least one slit valve50disposed therein and a valve control member55disposed adjacent the diaphragm45. By itself, the slit valve50is configured to actuate in both a proximal direction and a distal direction in response to a proximal pressure or a distal pressure, respectively. The valve control member55is configured to control deflection of the diaphragm45in a proximal direction thereby restricting actuation of the slit valve50in the proximal direction57. As a result, when the valve control member55is positioned adjacent the diaphragm45, the pressure differential which actuates the slit valve50in a distal direction is less than the pressure differential required to actuate the slit valve50in a proximal direction. In one embodiment, the diaphragm45is circular and the valve control member50is correspondingly circular. However, the diaphragm45and valve control member55can be oval, rectangular, or any other suitable shape. The valve control member55can be placed on a distal end of the diaphragm45, on a proximal end of the diaphragm45, or on both ends of the diaphragm45.

In one aspect of the invention, the valve control member55comprises at least one arm60extending from an outer portion65of the valve control member55to an inner portion66of the valve control member55. In this aspect of the invention, the arm can extend laterally across a portion of the face of the diaphragm or any other angular orientation. In another embodiment, the valve control member55comprises a plurality of arms60extending from an outer portion65of the valve control member55to a center portion66of the valve control member55. In one embodiment, a single slit valve50is disposed substantially within the center75of the diaphragm45and is substantially linear. In another embodiment several slit valves may be disposed either centrally or about the periphery of the diaphragm. Additionally, the slit valves may have a nonlinear orientation or may comprise a plurality of interconnected linear slits oriented in different directions.

Referring now toFIGS. 1,5,6, and7, in one embodiment, valve assembly35may include a pressure-activated valve80having an open circular proximal end85and an at least partially closed distal end90. Referring generally toFIG. 5, the distal end90of the valve80comprises at least a partially planar surface82having slit valves95oriented in different directions. The slits95have at least one common intersection100and are configured to actuate in a distal direction in response to a first pressure differential (e.g., less than or equal to approximately 2 psi). A portion105of the distal end90of the valve80is defined by an interior angle110of the at least two above-referenced slits95. An outer portion115of the distal end90of the valve80tapers from the distal end90of the valve80towards the proximal end85of the valve80. The tapering of the outer portion115of the valve80forms a channel120on the outer portion115of the distal end90of the valve80in the area defined by the interior angle110of the intersecting slits95.

As illustrated inFIG. 6, in one embodiment, at least one proximal-actuating slit valve125can be provided on the distal end90of the valve80. The proximal-actuating slit valve125can be configured to actuate in a proximal direction in response to a second pressure differential (e.g., greater than or equal to approximately 2 psi), wherein the second pressure differential is greater than the first pressure differential. As depicted inFIG. 7, the infusion of fluids through the valve80results in deflection of the distal actuating valve80. In one embodiment, the deflection of the valve80in the distal direction closes the proximal-actuating valve125. When the pressure gradient is reversed (e.g., aspiration is underway), the proximal-actuating valve125is closed. In another aspect, a plurality of proximal-actuating slits95can be disposed on the distal end of the valve90oriented to approximate the shape of a cruciform. Accordingly, the distal end90of valve80is separated by the slit valves into quadrants. In one aspect of the invention, channel120can be formed in each quadrant of the valve80. Moreover, the proximal-actuating slit125can be disposed with the channel120of the valve80. In an additional embodiment, the valve80is configured such that the center100of the cruciform is approximately collinear with the center of the circular proximal end85of the valve80. In an additional embodiment, the sum of the arc lengths130of each quadrant is equal to the circumference of the proximal end85of the valve80. For example, if the arc length130of one quadrant is equal to 0.5 inches the circumference of the proximal end85of valve80is approximately 2 inches.

Referring now toFIGS. 8 through 10, in one embodiment, a medical device for regulating fluid flow is disclosed comprising a valve housing150configured to attach to a proximal end of a catheter. The medical device further comprises a diaphragm155with at least one bidirectional slit valve160disposed therein, wherein the diaphragm approximates a dome structure165. The slit valve160may have linear or nonlinear orientations. The valve housing150is further configured to secure the diaphragm155at a peripheral portion170of the diaphragm155. A central portion175of the diaphragm155is positioned relative to the peripheral portion170of the diaphragm155such that when the peripheral portion170is secured by the valve housing150, the compressive forces acting on the peripheral portion170create moment forces which bias the slit valve160in a neutral position. Despite the moment forces which bias the slit valve160in a neutral position, the slit valve160is configured to flex in a distal direction in response to pressure (e.g., a gravity-induced liquid pressure). In one embodiment, the peripheral portion170of the diaphragm has a height which is at least twice the width of the hinge171of the diaphragm155. In another embodiment, the height of the peripheral portion170is approximately twice the width of the peripheral portion. In yet another embodiment, the peripheral portion170is compressed by the valve housing approximately five to 15 percent. In one embodiment, the peripheral portion170of the diaphragm155has a height that ranges from approximately 0.005 inches to 0.075 inches and a thickness of the central portion175of the diaphragm155ranges from approximately 0.001 to 0.003 inches.

Referring generally toFIGS. 1 and 8through12, in one embodiment, the valve housing150comprises a distal end185having a central hollow portion190configured to connect to a proximal end of a first portion of catheter assembly10, a distal end20of the first portion15of catheter assembly10is configured for placement into a vasculature of a patient20. The valve housing150further comprises a proximal portion195having a central hollow portion200configured to connect to a distal end41of a second portion40of catheter10. A proximal end42of the second portion40of catheter assembly10is configured to connect to a fluid source43and also connect to a fluid removal and fluid injection location44. The distal portion185and proximal portion195of the valve housing150mate at complimentary cut-away areas205securing the diaphragm155therebetween. All or part of the peripheral portion170of the diaphragm155may be secured by the valve housing150depending on the desired moment forces resulting from compression of the peripheral portion170. The distal portion185and proximal portion195of the valve housing155can be secured together through any suitable method (e.g., bonded or welded). In one embodiment, as illustrated inFIG. 8, the diaphragm155is secured such that it is perpendicular to the flow of fluid through the valve housing150. The diaphragm155may be substantially circular, oval, rectangular, or any other suitable shape.

In another embodiment, the diaphragm155further comprises at least one arm or protrusion210. The protrusion210may be placed on a proximal end of the diaphragm155to assist the slit valve160to return to a neutral position after aspiration. When the slit valve160opens during aspiration, the protrusion210contacts the valve housing150thereby creating a moment force opposite the direction of contact to assist the slit valve160to return to a neutral position after aspiration. Multiple protrusions may be added in different embodiments on both distal and/or proximal ends of the diaphragm155to optimize valve function.

In another embodiment, the diaphragm155is configured such that a portion of the proximal end of the diaphragm contiguous with the slit valve is thinner than an adjacent portion of the diaphragm. The thinner area215near the slit valve160assists in actuation of slit valve160as well as slit valve performance during gravity flow of fluids through the diaphragm155. In areas where the diaphragm is thinner, the diaphragm may be reinforced as illustrated inFIG. 9. The reinforced area220assists in returning the slit valve160to a neutral position by distributing moment forces coming from protrusion210. Additionally, the reinforced area220provides a secondary sealing surface225for an opposing valve face230in the event that the slit valve160is unable to return to a neutral position. In another aspect, the diaphragm155is configured such that valve hinge171is thinner than an adjacent portion of diaphragm155. The thinner area near of valve hinge171facilitates hinge activity under lower pressures (e.g., gravity-induced pressure).

As illustrated inFIGS. 11 and 12, in one embodiment, the diaphragm155comprises a plurality of unidirectional slit valves. The diaphragm155can have a distal-actuating slit valve240disposed in a central region of the diaphragm155and at least one proximal-actuating slit valve245disposed on a lateral portion of the diaphragm155. The distal-actuating slit valve240flexes in response to infusion-induced pressures and remains closed during aspiration. The at least one proximal-actuating slit valve245flexes in response to aspiration-induced pressures and remains closed during infusion procedures.

Referring toFIGS. 13 and 14, in one embodiment of the present invention, a diaphragm250is disclosed having at least one bidirectional slit valve255disposed therein. The diaphragm250approximates a dome structure260. The diaphragm250further comprises an annular member265which circumscribes the dome structure260. In one embodiment, the annular member265is oriented with its apex270in a proximal direction. In another embodiment, the annular member265is oriented with its apex275in a distal direction.

Referring now toFIGS. 1 and 15through17, in one embodiment, a valve assembly is disclosed comprising a valve housing300configured to secure a diaphragm305at a peripheral portion310of the diaphragm305. The diaphragm305has at least one slit valve315disposed therein and is oriented within the valve housing300at a direction which is at an obtuse angle relative to the direction of fluid flow through the valve housing300. The valve housing300comprises a distal end320having a central hollow portion325configured to connect to a proximal end30of a first portion15of catheter assembly10. A distal end20of the first portion15of catheter assembly10is configured for placement into a vasculature12of patient25. The valve housing300further comprises a proximal portion330having a central hollow portion335configured to connect to a distal end41of a second portion40of catheter assembly10. A proximal end42of the second portion40of catheter assembly10is configured to connect to a fluid source43and also connect to a fluid removal and fluid injection location44. The distal portion320and proximal portion330of the valve housing300mate at complimentary cut-away areas340securing the diaphragm305therebetween. All or part of the peripheral portion310of the diaphragm305may be secured by the valve housing300depending on the desired moment forces resulting from compression of the peripheral portion310. The diaphragm305can have a substantially circular shape, a substantially oval shape, a substantially rectangular shape, or any other suitable shape, and can also approximate a dome structure. The distal portion320and proximal portion330of the valve housing300can be secured together through any suitable method (e.g., bonded or welded). In another embodiment, the surface area of diaphragm305subjected to pressure actuation (e.g., not in contact with any portion of the valve housing300) is greater on a proximal end of the diaphragm305than a distal end of the diaphragm305. The amount of the slit valve315disposed in diaphragm305that is subject to pressure actuation (e.g., not in contact with any portion of the valve housing300) is equal on both distal and proximal ends of the diaphragm305. This can be accomplished by varying the shape or size of the distal portion320and proximal portion330of valve housing300.

Referring now toFIGS. 18 and 19, in an additional embodiment, the diaphragm narrows from a lateral portion345of the diaphragm305to an opposite lateral portion350of the diaphragm305. In another embodiment, the diaphragm305has two slit valves355disposed on opposing sides of the diaphragm305. Each slit valve355is unidirectional. A first valve is configured to actuate in a distal direction in response to an infusion-induced pressure differential. A second valve is configured to actuate in a proximal direction in response to an aspiration-induced pressure differential. The relative thickness of lateral portions of diaphragm305control the actuation pressure of the slit valves355.

Referring now toFIG. 20, in an additional aspect, a medical device for regulating fluid flow is disclosed comprising a generally cylindrical member370having a closed distal end375and an open proximal end380. The proximal end380further comprises a shoulder member385configured to be secured at least partially by a valve housing. The cylindrical member370has at least one slit valve390disposed therein being oriented parallel to a longitudinal axis of the cylindrical member370. In another aspect, the cylindrical member370further comprises a plurality of slit valves390disposed on the cylindrical member370.

Referring generally toFIGS. 21 and 22, a diaphragm400for regulating fluid flow is disclosed having at least one slit valve405disposed therein. The diaphragm400can be secured in a valve housing at a peripheral portion410of the diaphragm. In this embodiment, a proximal surface415of the diaphragm400is substantially planar. Likewise, a distal surface420of the diaphragm400is substantially planar. A central portion420of the diaphragm400is thinner than an outer region425of the diaphragm400. In another embodiment, the distal surface430of the diaphragm400is substantially planar and the proximal surface is substantially conical435. In another embodiment, referring generally toFIGS. 23 and 24, the proximal surface440of the diaphragm400is substantially planar and the distal surface of the diaphragm400approximates a spherical cap445. In another embodiment, the distal surface450of the diaphragm400approximates a spherical cap and the proximal surface455of the diaphragm400also approximates a spherical cap. The virtual centers of the opposing spherical caps of the diaphragm400can be collinear. The spherical cap on the distal surface455can be smaller than the spherical cap on the proximal surface450. In yet another embodiment, referring generally toFIGS. 25 and 26, a proximal surface460of the diaphragm400is substantially conical. The distal surface465of the diaphragm400is also substantially conical.

Any of the catheters described herein can be manufactured from any biocompatible material suitable for placement into a portion of a patient.

Although the above-described embodiments show a particular configuration of a pressure-actuated valve and valve assembly, such embodiments are exemplary. Accordingly, many different embodiments are contemplated and encompassed by this disclosure. It should also be understood that the device and method for controlling fluid flow through a catheter can be used with any method or device wherein fluids are administered to or removed from a patient.

While certain embodiments and details have been included herein for purposes of illustrating aspects of the instant disclosure, it will be apparent to those skilled in the art that various changes in the systems, apparatuses, and methods disclosed herein may be made without departing from the scope of the instant disclosure, which is defined, in part, in the appended claims. The words “including” and “having,” as used herein including the claims, shall have the same meaning as the word “comprising.”