Patent Publication Number: US-9884175-B2

Title: Automatic medical valve with a variable diameter seal

Description:
RELATED APPLICATION 
     The subject application claims priority to U.S. Provisional Application Ser. No. 62/151,835 filed on Apr. 23, 2015, the entire disclosure of which is incorporated by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present disclosure relates generally to medical devices and procedures. In particular, the present disclosure relates to hemostatic valves and systems, and methods of using the same. 
     2. Description of the Prior Art 
     This section provides background information related to the present disclosure which is not necessarily prior art. 
     Numerous procedures have been developed that involve the percutaneous insertion of a medical device into a body vessel of a patient, with the medical device being introduced into the vessel by a variety of known techniques. Each of these procedures must control the flow of bodily fluids when the medical device is inserted into the body vessel. Accordingly, medical valves, such as hemostatic valves, iris valves, laparoscopic ports, or the like, are often used to limit or prevent blood/fluid or CO 2 /gas loss during the procedure. 
     Hemostatic valves often incorporate a elastomeric slit septum disk to control fluid flow through the medical device. However, disk valves are subject to deformation with both time and use, and often can tear or become dislodged during insertion and/or withdrawal of the medical device. Furthermore, disk valves are not designed to provide an effective seal across a wide range of differently sized medical devices. Although the disk valve can be modified to accommodate these situations, such as with increased tensile and/or elongation properties, this modification leads to increased resistance, and thus require the use of excessive force when the medical device is inserted and withdrawn through the disk valve. 
     Iris valves can include an elastomeric sleeve that is disposed within a valve body and which is interconnected to a rotatable cap. When the cap is rotated in a first direction, an opening extending through the elastomeric sleeve is opened. Conversely, when the cap is rotated in a second opposite direction, the elastomeric sleeve is twisted and constricted to effectuate a closure of the elastomeric sleeve. However, if the operator stops the rotation, the elastomeric sleeve can revert, or recoil, back to the open position. Additionally, even when the elastomeric sleeve is held in the closed position, gaps or channels extend therethrough as a result of the twisting or enfolding required to effectuate a closure. Accordingly, fluid can leak through the iris valve in the closed position. Further, the continuous twisting and constricting of the elastomeric sleeve leads to wear of the sleeve, such as through tearing. 
     The drawbacks associated with the existing medical valves are further exemplified when one considers that a single medical valve often is used to insert multiple medical devices during a single procedure. For example, a hemostatic valve may be used first for introducing a delivery catheter, followed by an interventional catheter. In this example, the hemostatic valve must be able to provide a hemostatic seal under a variety of conditions, i.e., accommodate a variety of different sized medical devices. Additionally, the hemostatic valve device must be able to quickly adjust to use of each of these different medical devices, otherwise significant fluid loss can occur through the medical valve. 
     SUMMARY OF THE INVENTION 
     This section provides a general summary of the disclosure and is not intended to be a comprehensive disclosure of its full scope, aspects, objectives, and/or all of its features. 
     A medical valve assembly for use in inserting a medical device into a body vessel of a patient includes a tube extending between a proximal tube end and a distal tube end to define a passageway extending longitudinally along an axis between the tube ends. A plunger plate extends radially from the proximal tube end and a valve housing surrounds the tube about the proximal tube end. The valve housing extends from a proximal valve housing end to a distal valve housing end and includes a flange extending radially inwardly from the distal valve housing end, with the flange disposed in spaced relationship with respect to the plunger plate so as to define a distance dimension therebetween. An elastomeric seal is compressed between the plunger plate and the flange and has an inner diameter for use in establishing a variable seal of the medical valve assembly. The elastomeric seal is configured to automatically move one of the valve housing and the tube axially relative to the other when a medical device is inserted into the medical valve assembly. This axial movement varies the distance dimension between the plunger plate and the flange to allow the inner diameter of the elastomeric seal to variably adjust for sealing the medical valve assembly to the inserted medical device. Put another way, axial movement of one of the valve housing or the tube relative to the other in response to insertion of the medical device automatically varies a compression load on the elastomeric seal and allows the inner diameter of the elastomeric seal to be concurrently varied or adjusted in size. As a result, the size of the inner diameter of the elastomeric seal is able to quickly and automatically be adjusted to the size of the medical device by simply inserting the medical device into the medical valve assembly. This allows the medical valve assembly to be used with a variety of differently sized medical devices, even during the same procedure. 
     Further areas of applicability will become apparent from the description provided herein. The description and specific examples in this summary are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The drawings described herein are for illustrative purposes only of selected embodiments, and are not all possible implementations and thus are not intended to limit the scope of the present disclosure. 
         FIG. 1  is an environmental view of a first embodiment of the automatic medical valve assembly constructed in accordance with the principles of the present disclosure and illustrating a user interacting therewith; 
         FIG. 2  is an exploded perspective view of the first embodiment of the medical valve assembly; 
         FIG. 3  is a perspective view of the first embodiment of the medical valve assembly; 
         FIG. 4  is a cross-sectional view of the first embodiment of the medical valve assembly in a closed condition; 
         FIG. 5  is a cross-sectional view of the first embodiment of the medical valve assembly in an open condition; 
         FIG. 6  is a cross-sectional view of an hour-glass shaped elastomeric seal; 
         FIG. 7  is a cross-sectional view of the first embodiment of the medical valve including a slotted elastomeric seal disposed in a compressed or closed position; 
         FIG. 8  is a cross-sectional view of the slotted elastomeric seal in an un-compressed condition; 
         FIG. 9  is an environmental view of a second embodiment of the automatic medical valve assembly constructed in accordance with the principles of the present disclosure and illustrating a user interacting therewith; 
         FIG. 10  is an exploded perspective view of the second embodiment of the medical valve assembly; 
         FIG. 11  is a perspective view of the second embodiment of the medical valve assembly illustrating a clip disposed in a first position; 
         FIG. 12  is a perspective view of the second embodiment of the medical valve assembly illustrating the clip disposed in a second position; 
         FIG. 13  is a perspective view of the second embodiment of the medical valve assembly illustrating the clip disposed in a third position; and 
         FIG. 14  is a cross-sectional view of the second embodiment of the medical valve assembly in a closed condition and illustrated without the clip. 
     
    
    
     DESCRIPTION OF THE ENABLING EMBODIMENTS 
     Example embodiments will now be described more fully with reference to the accompanying drawings. The example embodiments are provided so that this disclosure will be thorough and fully convey the scope to those skilled in the art. Numerous specific details are set forth such as examples of specific components, devices, mechanisms, assemblies, and methods to provide a thorough understanding of various embodiments of the present disclosure. It will be apparent to those skilled in the art that specific details need not be employed, that example embodiments may be embodied in many different forms, and that neither should be construed to limit the scope of the disclosure. With this in mind, the present disclosure is generally directed to medical valve assemblies of the type used to introduce and withdrawal a medical device (i.e., a guide wire, catheter, stent, filter, etc.) into a body vessel of a patient. In particular, the medical valve assembly of the present disclosure incorporates an automatic variable seal arrangement for controlling an entry dimension of the variable seal arrangement. 
     Referring to the Figures, wherein like numerals indicate corresponding parts throughout the several views, an environmental view of a first embodiment of a medical valve assembly  10  and a second embodiment of a medical valve assembly  10 ′ is generally shown in  FIGS. 1 and 9 , respectively. As illustrated therein, each medical valve assembly  10 ,  10 ′ is of the type for use with a medical device  12 , such as a guide wire, catheter, stent, filter, vessel occlusion device, or the like. As will be explained in more detail below, as the medical device  12  is inserted and guided through the medical valve assembly  10  and into a body vessel  14  of a patient  16 , the medical valve assembly  10  will automatically effect a variable seal with the medical device  12 . 
     As best shown in  FIGS. 2, 4, 5, 10, and 14 , each medical valve assembly  10 ,  10 ′ includes a tube  20  extending between a proximal tube end  22  and a distal tube end  24  to define a passageway  26  extending longitudinally along an axis A between the tube ends  22 ,  24 , with the passageway  26  being sized to receive a variety of differently sized medical devices  12 . A plunger plate  28  extends radially from the proximal tube end  22  to define an outer plunger plate surface  30  extending in spaced and parallel relationship to the axis A. A valve housing  32  is disposed in surrounding relationship with the tube  20  about the proximal tube end  22  and extends from a proximal valve housing end  34  to a distal valve housing end  36  to overlay the outer plunger plate surface  30 . As best shown in  FIGS. 4, 5, and 14 , the valve housing  32  is disposed in spaced and axial or parallel relationship with the tube  20  between the distal valve housing end  36  and the plunger plate  28 . 
     The valve housing  32  includes a flange  38  extending radially inwardly from the proximal valve housing end  36 . The flange  38  is disposed in circumferentially spaced relationship with the plunger plate  28  to define a distance dimension D, as well as a cavity  40 , extending therebetween. The flange  38  also defines an opening  42  aligned on the axis A and that is sized to receive a variety of differently sized medical devices  12 . An elastomeric seal  44  is installed in the cavity  40  and normally is pre-loaded or compressed between the plunger plate  28  and the flange  38  by a compression member  48  (or spring). As will be described in more detail below, the elastomeric seal  44  establishes an automatic variable seal of the medical valve assembly  10  for sealing the medical valve assembly  10  to a variety of differently sized medical devices  12 . As best shown in  FIGS. 2-4 and 14 , the compression member  48  is disposed within the valve housing  32  and is compressed against the plunger plate  28  for effectuating a closing or decreasing of an inner diameter  46  of the elastomeric seal  44  to establish a closed condition of the medical valve assembly  10 . Put another way, the compression member  48  is under a slight preload to maintain the elastomeric seal  44  in a compressed state that achieves apposition of the inner diameter  46  of the elastomeric seal  44 , thus establishing the closed condition of the medical valve assembly  10 . As best shown in  FIGS. 4 and 14 , in the closed condition of the medical valve assembly  10 , the elastomeric seal  44  completely isolates or seals the opening  42  of the valve housing  32  from the passageway  26  of the tube  20 . In an aspect, the compression member  48  comprises a coil spring radially disposed between the valve housing  32  and the tube  20  and compressed between the first valve housing end  34  and the plunger plate  28 . However, any other suitable compression member, such as a leaf spring or the like, could be utilized without departing from the scope of the subject disclosure. 
     With the elastomeric seal  44  in its closed position, the medical device  12  is positioned to be inserted serially through the opening  42 , the inner diameter  46  of the elastomeric seal  44  and the passageway  26  of the medical valve assembly  10 . When a medical device  12  is inserted through the opening  42  of the valve housing  32 , the medical device  12  engages the elastomeric seal  44  with an insertion force that is transferred or exerted radially outward on the elastomeric seal  44 , causing the elastomeric seal  44  to axially expand and counteract the biasing force of the compression member  48  with an axial force that is exerted on the plunger plate  28  and the flange  38  by the axially expanded elastomeric seal  44 . Put another way, the insertion force of the medical device  12  is transferred through the elastomeric seal  44  to compress the compression member  48  and effectuate an axial movement of one of the valve housing  32  or the tube  20  relative to the other. The increased distance dimension D between the plunger plate  28  and the flange  38  changes the compression load exerted on the elastomeric seal  44  which, in turn, allows the inner diameter  46  of the elastomeric seal  44  to be expanded or increased in size to establish the open condition of the medical valve assembly  10 . According to an aspect, the automatic adjustment of the inner diameter  46  of the elastomeric seal  44  increases proportionately with the distance dimension D. Thus, the medical valve  12  allows the user to automatically establish the open condition of the medical valve assembly  10  simply by inserting the medical device  12  into the medical valve assembly  10  and engaging the elastomeric seal  44 . When the medical device  12  is removed from the medical valve assembly  10 , the biasing force of the compression member  48  compresses the elastomeric seal  44  back to its original size to effectuate a reduction or decrease in the inner diameter  46  of the elastomeric seal  44  to re-establish the closed condition of the medical valve assembly  10 . As best shown in  FIGS. 4 and 5 , when the valve housing  32  or the tube  20  is axially moved, the plunger plate  28  or the valve housing  32  axially slides relative to the other along the outer plunger plate surface  30 . The outer plunger plate surface  30  guides a sliding axial movement between the valve housing  32  and the tube  20 . 
     In a preferred aspect, an end cap  50  is mechanically interconnected to the valve housing  32  at the distal valve housing end  36  and is disposed in surrounding relationship around the tube  20 . The end cap  50  establishes a shoulder  52  extending radially inward from the valve housing  32  and which is disposed in engagement with the compression member  48 . As best shown in  FIGS. 2 and 10 , the end cap  50  defines an end cap opening  54  disposed concentrically around the distal tube end  24  of the tube  30  for serving as a guide for the tube  20 , keeping the tube  20  concentric to the valve housing  32  and the elastomeric seal  44 . As best shown in  FIGS. 2 and 10 , in each embodiment of the medical valve assembly  10 ,  10 ′, the end cap  50  includes a plurality of locking tabs  56  extending radially therefrom and the valve housing  32  defines a plurality of corresponding locking apertures  58  disposed circumferentially about the distal valve housing end  36  for establishing the mechanical interlocked relationship between the end cap  50  and the valve housing  32 . 
     As best shown in  FIGS. 2, 3, 5, 10, and 14 , a hub  60  is interconnected to the distal end  24  of the tube  20  for facilitating assembly of the medical valve assembly  10 ,  10 ′ to an introducer sheath  62  or the like. As best shown in  FIGS. 2 and 3 , the hub  60  has a tapered portion  64  disposed adjacent a distal end of the medical valve assembly  10  for fitting the introducer sheath  64  over the tapered portion  64  of the hub  60 . The hub  60  includes threads  66  disposed next adjacent the tapered portion  64  for allowing a compression nut  68  to be threadingly secured to the hub  60  for establishing a compression fit of the introducer sheath  62  between the compression nut  68  and the tapered portion  64  of the hub  60 . As best shown in  FIGS. 2 and 10 , the tube  20  includes an o-ring  70  disposed about the distal tube end  24  to establish a sealed relationship between the tube  20  and the hub  60 . 
     As best shown in  FIGS. 2 and 10 , the tube  20  defines an access hole  72  extending from the plunger plate surface  30  and radially through the plunger plate  28  to dispose the access hole  72  in fluid communication with the passageway  26 . As best shown in  FIGS. 1 and 9-13 , the access hole  72  is connectable to an extension tube  74  and stop cock  76  for facilitating the flushing of the medical valve assembly  10  and/or the medical device  12  when inserted into the body vessel  14 . As best shown in  FIGS. 2, 3 and 10 , the valve housing  32  can include at least one track  78  extending axially from the distal valve housing end  36  for receiving the extension tube  74  during attachment to the access hole  72 . As the valve housing  32  or the tube  20  are axially moved relative to the other, the extension tube  74  is able to slide within the track  78  to prevent the extension tube  74  and stop cock  76  from being dislodged or accidentally removed from the access hole  72 . If the medical application associated with the medical valve assembly  10 ,  10 ′ does not require flushing or aspirating capabilities, the access hole  72  would preferably not be present or could alternatively be plugged. 
     As best shown in  FIGS. 5, 6, 7 and 14 , the elastomeric seal  44  extends from a proximal seal end  80  to a distal seal end  82  to define a pair of end portions  84  disposed about the seal ends  80 ,  82 , each separated by a center portion  86 . In each preferred embodiment of the medical valve assembly  10 ,  10 ′, each of the end portions  84  are attached, secured or bonded respectively to the plunger plate  28  or the proximal valve housing end  34  of the valve housing  32  to prevent displacement of the elastomeric seal  44  and avoid the impingement of the elastomeric seal  34  between various medical devices  12 , such as a lumen, catheter, or the like, entering or disposed within the medical valve assembly  10 . As best shown in  FIG. 6 , in an aspect, the inner diameter  46  of the elastomeric seal  44  is tapered radially inwards from the end portions  84  towards a middle of the center portion  86  in a non-compressed state of the elastomeric seal  44  to define an hour-glass cross-sectional shape of the elastomeric seal  44 . As best shown in  FIG. 7 , according to another aspect, the inner diameter  46  extends circumferentially in parallel relationship with the axis A between the seal ends  80 ,  82  in a non-compressed state of the elastomeric seal  44 . The elastomeric seal  44  defines a pair of slots  88  each extending radially inward from the inner diameter  46  and disposed between a respective end portion  84  and the center portion  86 . In either aspect, the hour-glass cross-sectional shape or the slots  88  facilitate a compression of the elastomeric seal  44 , allowing the center portion  86  to move radially inward during compression to establish the closed condition of the medical valve assembly  10 . 
     As best shown in  FIGS. 9-13 , the second embodiment of the medical valve assembly  10 ′ includes a clip  90  slidably and removably disposed over the proximal valve housing end  34  of the valve housing  32  for allowing a user of the medical valve assembly  10 ′ to pre-open the elastomeric seal  44  prior to insertion of the medical device  12  into the medical valve assembly  10 ′. The pre-opening of the elastomeric seal  44  is advantageous when a medical device  12  for use with the medical valve assembly  10 ′ is not sized or tapered at its insertion end to easily facilitate the initial automatic movement of the valve housing  32  and the tube  20  relative to the other to automatically open the medical valve assembly  10 ′. As will be described in more detail below, the clip  90  can also maintain the elastomeric seal  44  in a slightly opened position prior to use, such as when the medical valve assembly  10 ′ is being stored or shipped, to increase the shelf life of the medical valve assembly  10 ′ by reducing material creep, material sticking, or distortion of the elastomeric seal. Put another way, maintaining the elastomeric seal  44  in a slightly opened position keeps or reduces the mechanical load on various parts of the medical valve assembly  10 ′. Additionally, maintaining the medical valve assembly  10 ′ in a slightly open position allows sterilization gases to pass through the elastomeric seal  44  and the tube  20  during a sterilization of the medical valve assembly  10 ′. 
     As best shown in  FIGS. 10-13 , in the second embodiment of the medical valve assembly  10 ′, a proximal end of the hub  60  includes a curved or tapered profile and the clip  90  includes a first curved portion  92  and a second curved portion  94  each having a curvature profile that corresponds to the curved or tapered profile of the hub  60 . The proximal valve housing end  34  defines a pair of guides  98  and the clip  90  includes a pair of rails  96  each disposed in mating and slidable relationship with a respective guide  98  when the clip  90  is disposed over the proximal valve housing end  34  of the valve housing  32 . 
     As best shown in  FIG. 11 , when the clip  90  is initially disposed over the proximal valve housing end  34 , the rails  96  mate and slide within the guides  98  to dispose the first curved portion  92  of the clip  90  in abutting and mating relationship with the curved profile of the hub  60  and define a first position of the clip  90 . This first position effectuates a small axial movement of the valve housing  32  relative to the tube  20  for maintaining the elastomeric seal  44  in the slightly opened position. Put another way, when the clip  90  is disposed in the first position, a profile of the first curved portion  92  causes the pair of rails  96  to pull back on each of the respective guides  98 , which axially pulls the valve housing  32  away from the tube  20  to allow the elastomeric seal  44  to axially expand and slightly increase the inner diameter of the elastomeric seal  44 . As best shown in  FIG. 11 , since the first curved portion  92  of the clip  90  is sized to correspond to the curved profile of the hub  60 , the clip  90  can remain in a fixed or stationary condition once placed in this first position until the clip  90  is removed by a user or advanced to the second position as described immediately below. 
     As best shown in  FIG. 12 , a user of the medical valve assembly  10 ′ can advance the clip  90  from its first position to dispose the second curved portion  94  in abutting and mating relationship with the curved profile of the hub  60  and define a second position of the clip  90 . This second position returns the valve housing  32 , and thus the elastomeric seal  44 , back to their original and un-opened positions. Put another way, when the clip  90  is moved or advanced from the first position to the second position, a profile of the second curved portion  94  allows the pair of rails  96  to release their axial pull on each of the respective guides  98 , which axially moves the valve housing  32  back towards the tube  20  and allows the compression member  48  to re-compress elastomeric seal  44  and re-close the medical valve assembly  10 ′. As best shown in  FIG. 12 , since the second curved portion  94  of the clip  90  is sized to correspond to the curved profile of the hub  60 , the clip  90  can remain in a fixed or stationary condition in this second position until the clip  90  is returned to the first position or advanced to a third position, as will described immediately below. When the clip  90  is disposed in the second position, the clip  90  does not impact or affect the functionality of the medical valve assembly  10 ′, allowing the medical valve assembly  10 ′ to operate according to the aforementioned automatic principles. Accordingly, the clip  90  defines a clip opening  100  which is disposed in aligned relationship with the opening  42  of the valve housing  32  in the second position to allow the medical device  12  to be inserted serially through the clip opening  100 , the opening  42 , the inner diameter  46  of the elastomeric seal  44  and the passageway of the medical valve assembly  10 ′. 
     As best shown in  FIG. 13 , a user of the medical valve assembly  10 ′ can advance the clip  90  from its second position to a third position by pushing on the clip  90  perpendicular to the axis A to slide the pair of guides  98  within each respective rail  96 . The movement of the clip  90  slides the second curved portion  94  along the curved profile of the hub  60  to effectuate a manual axial movement of the valve housing  32  in the upward/proximal direction relative to the tube  20  for pre-opening the medical valve assembly  10 ′. Put another way, when the clip  90  is advanced from the second position towards the third position, the sliding movement of the hub  60  along the profile of the second curved portion  94  causes the pair of rails  96  to push upward/proximal on each of the respective guides  98  while radially sliding therein, which movement axially pulls the valve housing  32  away from the tube  20  to allow the elastomeric seal  44  to axially expand and increase the inner diameter of the elastomeric seal  44 . As mentioned previously, this manual movement of the clip  90  from the second position to the third position allows a user of the medical valve assembly  10 ′ to pre-open the elastomeric seal  44  prior to insertion of the medical device  12  into the medical valve assembly  10 ′, such as when a medical device  12  being inserted into the medical valve assembly  10 ′ is not sized or tapered to easily facilitate the initial automatic movement of the medical valve assembly  10 ′. As best shown in  FIG. 13 , the clip  90  additionally defines a slot  102  extending radially from the clip opening  100  and which is disposed in aligned relationship with the opening  42  of the valve housing  32  in the third position to allow the medical device  12  to be inserted serially through the slot  102 , the opening  42  of the valve housing  36 , the inner diameter  46  of the elastomeric seal  44  and the passageway of the medical valve assembly  10  while the clip is manually held in its third position. Once the medical device  12  is inserted into the medical valve assembly  10 ′, a user can then release the manual pressure on the clip  90  which returns the clip  90  to the second position and allows the compression member  48  to compress the elastomeric seal  44  and automatically create a seal around the inserted medical device  12 . 
     Although not expressly shown, a wiper seal can be disposed within the opening  42  of the valve housing  32 . Additionally, in an aspect, the tube  20 , valve housing  32 , and end cap  50  are thermoplastic molded components and the elastomeric seal  44  is comprised of molded silicone. However, each of these components can be fabricated using other techniques or other elastomeric materials without departing from the scope of the subject disclosure. 
     The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.