Patent Publication Number: US-2023134876-A1

Title: Low profile access sheaths

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application claims priority to U.S. Provisional Patent App. Nos. 63/272,750, filed 28 Oct. 2021, and 63/413,098, filed 4 Oct. 2022, the entire contents of each of which are incorporated by reference herein. 
    
    
     TECHNICAL FIELD 
     The present disclosure is directed to non-peel away introducer sheath assemblies and dilator assemblies that may permit the introduction of one or more medical devices into a patient at a single insertion site, such introducer sheath assemblies having a hemostatic valve to reduce or eliminate the discharge of body fluids from the patient through the insertion site of an introducer sheath assembly. 
     BACKGROUND 
     A mechanical circulatory support device (e.g., an intracardiac heart pump assembly) or other medical devices, can be introduced into a patient in various ways. A common approach is to introduce the device through the vascular system either surgically or percutaneously during a cardiac procedure. If the medical device is expected to remain in the patient for an extended period of time, typically utilized peel-away introducer sheaths may be peeled away and replaced with a smaller diameter sheath preinstalled on the medical device (e.g., a repositioning sheath), to reduce the risk of blockages in the bloodstream. 
     BRIEF SUMMARY 
     A first aspect is drawn to a device for insertion into a vasculature of a patient, where the device comprises a primary tubular sheath body, an intermediate tubular sheath body connected to a proximal end of the primary tubular sheath body, and a hub connected to a proximal portion of the intermediate tubular sheath body. The primary tubular sheath body is comprised of a first material, the intermediate tubular sheath body is comprised of a second material, and the hub is comprised of a third material, where a theoretical interfacial bonding strength between the first and second material, and a theoretical interfacial bonding strength between the third material and the second material, are both greater than a theoretical interfacial bonding strength between the first material and the third material. 
     In some embodiments, the intermediate tubular sheath body may have a first inner diameter at its distal end, and a second inner diameter at an axial distance proximal to the distal end, the second inner diameter being greater than the first inner diameter. In some embodiments, the second inner diameter may be between 5 mm and 6 mm. 
     In some embodiments, the first material may comprise a polyether block amide (PEBA). In some embodiments, the second material may comprise a thermoplastic styrene-butadiene copolymer. In some embodiments, the third material may comprise acrylonitrile butadiene styrene. 
     In some embodiments, the primary tubular sheath body may comprise a plurality of layers. These layers may include, e.g., a frame layer and an outer jacket. In some embodiments, the frame layer may comprise nitinol, and the outer jacket may comprise a polyether block amide (PEBA). 
     In some embodiments, the device may include a sideport extending from the hub. 
     In some embodiments, the hub may comprise a rotatable portion that is rotatable relative to the hub, the primary tubular sheath body, and the intermediate tubular sheath body, the rotatable portion being connected to a distal portion of the hub. In some embodiments, the rotatable portion may be rotatable (i.e., capable of being rotated) by at least 180 degrees. In some embodiments, the rotatable portion may be rotatable by at least 360 degrees. In some embodiments, the rotatable portion may be configured to allow a sideport extending from the hub to lie flat against a patient. In some embodiments, the rotatable portion may comprise a butterfly, a suture pad, or a combination thereof. 
     A second aspect is drawn to an apparatus comprising a hub, a sheath with a tubular sheath body operably coupled to the hub, a dilator having a dilator body receivable through the tubular sheath body, a dilator hub coupled to a proximal end of the dilator body, and a dilator handle coupled to the dilator cap. The hub includes one or more threads extending partially around circumference of hub, each thread having a locking portion that has a different axial thickness than a different portion of the thread. The tubular sheath body extending from a proximal end to a distal end, the proximal end operably coupled to the hub, and the dilator cap includes a groove or channel configured to receive the thread when the dilator is received through the sheath body, the groove or channel configured to have a ridge or depression adapted to engage with the locking portion of the thread. 
     In some embodiments, the groove or channel may be configured to have a ridge and the locking portion has a smaller axial thickness than that a different portion of the thread. In some embodiments, a height of the ridge or depression may be the same as a difference in the axial thickness between the locking portion and the different portion. 
     In some embodiments, the hub and the dilator cap may each contain an indicator on an external surface configured to convey when the groove or channel is aligned with the thread prior to being locked into position. 
     In some embodiments, the dilator cap may define an opening extending from a proximal surface to a distal surface along a central axis, the opening having a central circular portion and one or more spokes extending outward from the central circular portion, each spoke configured to align with a ridge on a distal surface of the dilator handle. 
     In some embodiments, the apparatus is configured to provide an indicium to a user that the dilator is locked into place, such as an auditory sound, a vibration through the dilator handle, or a combination thereof. 
     A third aspect is drawn to a hemostatic valve assembly, comprising a foam member configured to secure an elastomeric member at least partially within a housing and provide structural support against a proximal end of the elastomeric member, the foam member having a proximal surface defining a first opening extending along a longitudinal axis from the proximal surface to a distal surface a longitudinal axis of the hemostatic valve assembly, and the foam member having at least one visibly identifiable portion a predetermined distance from at least one edge of the first opening. 
     In some embodiments, the foam may contain a silicone oil. In some embodiments, the first opening may be laser cut. 
     In some embodiments, the at least one visibly identifiable portion may comprise one or more additional openings extending at least partially from the proximal surface towards the distal surface. In some embodiments, each of the one or more additional openings may be equidistant from the at least one edge. In some embodiments, each of the one or more additional openings may have a diameter less than 0.5 mm. In some embodiments, the one or more additional openings may comprise between 2 and 4 additional openings. 
     In some embodiments, the at least one visible identifiable portion may comprise a portion that is visibly darker or lighter than a different portion of the foam. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG.  1 A  is a 2D schematic of an embodiment of an introducer sheath with a hemostatic valve. 
         FIG.  1 B  is a 2D schematic of an embodiment of an introducer sheath with a hemostatic valve and a dilator assembly inserted. 
         FIG.  2    is a 2D schematic of an embodiment of a hub. 
         FIGS.  3 A and  3 B  are orthogonal representations of embodiments of dilator caps. 
         FIG.  4    is an orthogonal representation of an embodiment of a dilator handle. 
         FIG.  5    is an orthogonal representation of an embodiment of a foam member of a hemostatic valve. 
         FIGS.  6 A- 6 D  are 2D representations of different embodiments of the foam member. 
         FIG.  7    is a representation of a still another embodiment of a foam member. 
         FIGS.  8 A and  8 B  are representations of a foam member in a hub. 
     
    
    
     DETAILED DESCRIPTION 
     For mechanical circulatory support devices, peel-away introducer sheaths may be used when the device is expected to remain in a patient for an extended period of time (e.g., by peeling away the introducer sheath and replacing it with a smaller diameter sheath preinstalled on the medical device). However, as it becomes more desirable to utilize a single point of insertion into the body to introduce multiple medical devices, peel-away introducers may become less desirable due to the intentionally reduced sidewall strength of such introducers. Additionally, typical peel-away introducers have a large outer diameter, which can undesirably obstruct blood flow past the introducer and lead to lower limb ischemia. 
     Thus, the inventors have appreciated that a low-profile non-peel away introducer sheath may be desirable. However, to maintain the desirable features of such sheaths, further changes to the design may be required, as the dimensions cannot simply be reduced proportionally and remain useable and manufacturable. 
     To that end, a low-profile non-peel away introducer sheath assembly, and dilator assemblies that enable such sheaths to be useful, that incorporate design features that allow the benefits of current non-peel away introducer sheaths while remaining manufacturable are desirable. 
     As seen in  FIGS.  1 A and  1 B , a system for insertion into the vasculature of a patient can be seen. The system generally comprises a hub  40  operably connected to a sheath  105 , the hub comprising a hemostatic valve  200  through which, e.g., a dilator assembly  110 , a heart pump, or other medical devices may be inserted. 
     A first aspect of the present disclosure is drawn to a device  10  for insertion into a vasculature of a patient can be seen. The device  10  may include a primary tubular sheath body  20  coupled to a distal end of an intermediate tubular sheath body  30 , and a hub  40  coupled to a proximal portion of the intermediate tubular sheath body  30 . The hub  40  may be connected to a sideport  50 . A rotatable portion  60  or member may be operably coupled to a distal end of the hub. 
     Primary Tubular Sheath Body 
     The primary tubular sheath body  20  may include a first material, and the primary tubular sheath body may extend from a proximal end  21  to a distal end  22 . 
     In some embodiments, the first material may comprise a polyether block amide (PEBA), such as the PEBAX® elastomers sold by Arkema. 
     In some embodiments, the primary tubular sheath body  20  may comprise a plurality of layers. In some embodiments, the primary tubular sheath body  20  may comprise an outer jacket  23  (which may comprise or consist of a PEBA), and an inner frame layer  24  (which may comprise or consist of nitinol). 
     Intermediate Tubular Sheath Body 
     The device also may include an intermediate tubular sheath body  30  (see  FIGS.  1 A and  1 B ) comprising or consisting of a second material, the intermediate sheath body extending from a proximal end  31  to a distal end  32 . The distal end  32  of the intermediate tubular sheath body  30  may br connected to the proximal end  21  of the primary tubular sheath body  20 . In some embodiments, the distal end of the intermediate tubular sheath body may be butt welded to the proximal end of the primary tubular sheath body, though it should be understood that other types of joints between the primary and intermediate tubular sheath bodies may be suitable. 
     In some embodiments, the intermediate tubular sheath body  30  may comprise or consist of a thermoplastic styrene-butadiene copolymer, such as the STYROLUX® resins sold by Entec Polymers. 
     In some embodiments, the intermediate tubular sheath body  30  may have a proximal portion  35  with a constant inner diameter  39  and a distal portion  33  that necks down linearly from the inner diameter  39  of the proximal portion to a smaller inner diameter  38  at the distal end  32 . In some embodiments, the intermediate tubular sheath body may have a first inner diameter  38  at the distal end  32 , and a second inner diameter  39  at an axial distance proximal to the distal end  34 . In some embodiments, the second inner diameter  39  may be greater than the first inner diameter. In some embodiments, the second inner diameter  39  is between 5 mm and 6 mm. In some embodiments, this inner diameter may be the same as the inner diameter of the primary tubular sheath. 
     Hub 
     The device also may comprise a hub  40  (see, e.g.,  FIG.  1 A ). The hub may comprise or consist of a third material, and the hub  40  may be connected to a proximal portion  35  of the intermediate sheath body  30  and be separated from the primary tubular sheath body  20  by the intermediate tubular sheath body  30 . 
     In some embodiments, the third material may be acrylonitrile butadiene styrene. 
     In some embodiments (see, e.g.,  FIGS.  1 A and  1 B ), an inner surface  41  of the hub  40  may be connected to a portion of the outer surface  36  of the intermediate tubular sheath body  30  and not connected with the primary tubular sheath body  20 . In some embodiments, the hub is only connected to the proximal portion  35  of the intermediate tubular sheath body  30  with a constant diameter  39  and is not connected to the distal portion  33  that necks down to a smaller inner diameter. 
     Because different properties are needed for the hub than for the primary tubular sheath body, the materials that comprise each of these parts are necessarily different, and these differences often result in the two components not being able to bond the components together effectively. Thus, in some embodiments, the intermediate layer aids in bonding by having an intermediate layer that the two components bond to more effectively than each other. Therefore, in the present disclosure, the first material, second material, and third material may be configured such that a theoretical interfacial bonding strength between the first and second material, and a theoretical interfacial bonding strength between the third material and the second material, are both greater than a theoretical interfacial bonding strength between the first material and the third material. As is known in the art, Interfacial bonding strength (IBS) is the strength that bonds two layers at the interface, and can be tested via, e.g., tensile tests or shear tests, although tensile is more typically utilized. 
     Sideport 
     As also shown in  FIGS.  1 A and  1 B , the device may also comprise a sideport  50  extending from the hub  40 . A first end  51  of the sideport  50  may be connected an entrance  44  defined by an exterior surface  42  of the hub  40  that extends to the interior surface  41  of the hub  40 . 
     Rotatable Portion 
     The device may also comprise a rotatable portion  60  (see e.g.,  FIG.  1 A ) that is rotatable around a central axis relative to the primary tubular sheath body  20 . In some embodiments, the intermediate tubular sheath body  30 , the hub  40 , and the rotatable portion may be connected to a distal portion of the hub  40 . 
     In some embodiments, the rotatable portion  60  may be attached in a non-removable (or not easily removable) fashion, such as via a plurality of snap-fit joints  61 . In some embodiments, the rotatable portion may comprise a butterfly, a suture pad, or a combination thereof. 
     In some embodiments, the rotatable portion  60  may be rotatable around a central axis (in  FIGS.  1 A and  1 B , the central axis being the centerline of the primary tubular sheath body  20  and the intermediate tubular sheath body  30 ) by at least 180 degrees. For example, in some embodiments, the rotatable portion (when attached to a patient) can still allow the hub to be rotated such that (at a minimum) the sideport can face towards the right side of the patient or towards the left side of the patient. In some embodiments, the rotatable portion  60  may be rotatable around a central axis by at least 360 degrees, up to and including being freely rotatable without restriction. 
     In some embodiments, the rotatable portion  60  may be configured to allow the sideport  50  extending from the hub  40  to lie substantially flat against a patient, regardless of the orientation of the rotatable portion  60  on the body of the patient. For example, in some embodiments, by allowing the hub to be rotated such that the entrance  44  of the hub where the .sideport  50  is connected to is directed towards a patient&#39;s body (or at least, not be directed away from the patient&#39;s body), the sideport can readily lie substantially flat against a patient. 
     In some embodiments, the rotatable portion  60  may be configured to encircle the portion of the device  10  where some or all of the intermediate tubular sheath body  30  is positioned, as well as encircling the point of connection between the primary tubular sheath body  20  and the intermediate tubular sheath body  30  (e.g., encircling at least a portion of the proximal end of the tubular sheath body  20 ). 
     Also disclosed is an apparatus (or system)  100 . In some embodiments, the apparatus  100  comprises a hub  40 , a sheath  105 , and a dilator  110 . 
     Hub 
     Referring to  FIG.  2   , a hub  40  can be seen, the hub having a distal end  46  and a proximal end  47 . The hub  40  may include one or more threads  43  (two threads are shown in  FIG.  2    by way of an example), each thread extending at least partially around the circumference of hub  40 . As will be appreciated, the threads may have other suitable arrangements in other embodiments. As shown in  FIG.  2   , the threads  43  may be disposed in a proximal portion  101  of the hub  40 , at or near the proximal end  47 . 
     As shown in  FIG.  2   , in some embodiments, each thread may have portions with different axial thicknesses (e.g., a thickness of the thread in an axial direction). For example, in one embodiment, each thread  43  may have a first, locking portion  104  with a first axial thickness  49  that may be different than a second axial thickness  48  in a second portion  103  of each thread  43 . 
     In some embodiments, the locking portion  104  may have first axial thickness  49  that is less than the second axial thickness  48  of the second portion  103 . In some embodiments, the locking portion  104  may have first axial thickness  49  that is greater than the second axial thickness  48  of the second portion  103 . 
     In some embodiments, each thread may have one locking portion  104  and one second portion  103 . In some embodiments, each thread may have one locking portion  104  and two second portions  103  (one on each side of the locking portion). 
     In some embodiments, the interface  109  of the locking portion  104  and the second portion  103  may extend in a non-radial direction. In some embodiments, the interface  109  of the locking portion  104  and the second portion  103  may extend in a radial direction. 
     The hub  40  may also comprise an indicator  107 , such as a shape or design molded or etched into or onto an outer surface of the hub, to aid in aligning the hub  40  and the dilator  110 . 
     Sheath 
     Referring again to  FIG.  1 B , the apparatus  100  also may comprise a sheath  105 . The sheath  105  may include a primary tubular sheath body  20  extending from a proximal end  21  to a distal end  22 . In some embodiments, the proximal end  21  may be operably coupled to the hub  40 , such as via an intermediate tubular sheath body  30  as described previously. 
     Dilator 
     The apparatus  100  also may include a dilator  110  (see, e.g.,  FIG.  1 B ). The dilator  110  may comprise a dilator body  120  receivable through the tubular sheath body  20 , and a dilator hub  125  coupled to a proximal portion of the dilator body  120 . The dilator hub  125  may comprise or consist of a dilator cap  130  and a dilator handle  140 . In some embodiments, the dilator handle  140  may be coupled to a proximal surface of the dilator cap  130 . 
     Referring to  FIG.  3 A , the dilator cap  130  may include at least one groove or channel  131  configured to receive the one or more threads  43  on the hub  40  when the dilator body  120  is received through the primary tubular sheath body  20 . In this regard, the size and shape of the at least one groove or channel  131  may correspond to the size and shape of the one or more threads  43  on the hub  40 . 
     In some embodiments, one or more of the grooves or channels  131  may be configured to have a ridge or depression  132  adapted to engage with the locking portion  104  of the thread  43 . In some embodiments, every groove or channel  131  may be configured with a ridge or depression  132  adapted to engage with the respective locking portion of the respective thread. In some embodiments, the groove or channel  131  may be configured to have the ridge  132 , and the locking portion may a smaller first axial thickness than the second portion of the thread (e.g., to allow for engagement between the ridge or depression and the locking portion). 
     In some embodiments, the dilator cap  130  may also contain an indicator  136 , such as a shape or design molded or etched into or onto an outer surface of the dilator cap  130 , to aid in aligning the hub  40  and the dilator  110  (and more specifically, aligning the dilator cap and the hub). In some embodiments, the hub  40  and the dilator cap  130  may each contain an indicator ( 107 ,  136 ) configured to convey when the groove or channel is aligned with the thread prior to being locked into position. In some embodiments, the hub  40  and the dilator cap  130  may each contain an indicator ( 107 ,  136 ) configured to convey when the groove or channel is locked into the locked position. In some embodiments, the dilator cap  130  may contain one indicator ( 136 ) and the hub may contain two indicators ( 107 ) configured to convey both when the groove or channel is aligned with the thread prior to being locked in the locked position, and also when the groove or channel is locked in the locked position. 
     The dilator cap  130  may be configured such that any ridge or depression  132  has a height in the axial direction that is equal or substantially equal to the difference in height between the locking portion  104  and the (one or more) second portion  103 . 
     The dilator  110  may be configured to provide an indicium, such as a non-visual indicium, to a user that the dilator is locked into place (e.g., locked onto the hub). By configuring the dimensions and composition of the components, such as the dilator cap  130 , the dilator can be configured to, e.g., produce an auditory sound. For example, the dilator cap may produce a noticeable “click” sound, a vibration through the dilator handle, or a combination thereof when the dilator is locked into place. Other indicia may be utilized as appropriate to indicate a locking status of the dilator. 
     In some embodiments, the dilator cap  130  has a proximal surface  137  that defines an opening  133  extending from the proximal surface  137  to a distal surface  138  of the dilator cap (see, e.g.,  FIG.  3 A ). The opening  133  may be circular or substantially circular in shape, and the center of the opening may be aligned with a centerline  135  of the dilator cap  130 . In some embodiments, the opening  133  may have a diameter between, e.g., 7 and 8 mm. The proximal surface  137  may also define one or more “spoke” or “wing” channels  134  that extend outwardly from the central opening  133 . In this regard, the spoke or wing channels  134  are additional openings defined by the proximal surface and extend from the proximal surface  137  to the distal surface  138 . 
     In some embodiments, the central opening  133  may have an inner surface  150  that includes straight-cut sides extending in the axial direction (e.g., parallel to the central axis  135 ) from the proximal surface  137  to the distal surface  138 . In some embodiments, a proximal edge  151  of the inner surface  150  of the central opening may be shaped to ease assembly. Referring to  FIG.  3 B , the inner surface  150  of the central opening  133  also may include a chamfer  152  at the proximal surface  137  (e.g., at least a portion of the proximal edge may be chamfered). In such embodiments, the inner surface central opening  133  may be rounded at the proximal surface  137  (e.g., at least a portion of the proximal edge may be rounded). 
     In some embodiments, there may be additional text or images provided on the proximal surface  137 . For example, in some embodiments, one or more words or icons are embossed on the proximal surface. In some embodiments, such words or icons provides directions or use instructions to a user (e.g., “twist” or “push”), or information related to the size of the opening of the dilator (e.g., “14F” to indicating the dilator is a 14 French dilator, etc.). 
     In some embodiments, the spokes or wing channels  134  may help align the dilator handle  140  with the dilator cap  130 . In some embodiments, the spokes or wings  134  may aid in transferring force from the handle to the cap, such as when the handle and cap are coupled to one another. 
     In some embodiments, a single spoke or wing channel  134  may be present. In some embodiments, the distal cap  130  comprises between 2 and 4 spoke or wing channels  134 . In some embodiments, the spoke or wing channel  134  are symmetrically arranged around the central opening  133 . In some embodiments, each spoke or wing channel  134  may extend radially a same distance  139  from an edge of the central opening  133  towards an outer edge of the proximal surface. In some embodiments, each spoke or wing channel may have the same size and shape. As will be appreciated, the spoke or wing channels may have a size and shape that corresponds to corresponding coupling regions on the dilator handle. 
     Referring to  FIG.  4   , an embodiment of a dilator handle  140  is seen. The dilator handle  140  may include a dilator handle body  141  that has a proximal end  142  and a distal end  143 . The dilator handle body  141  may define a central lumen  144  extending from the proximal end  142  to the distal end  143 . 
     In some embodiments, the distal portion of the dilator handle may comprise a coupling portion  145  that is configured to allow the dilator handle  140  to be coupled to the dilator cap  130 . In some embodiments, the coupling portion may include one or more locking extensions configured to pass through the central opening and the one or more spoke or wing channels on the dilator cap. For example, in some embodiments, the coupling portion  145  comprises a central extension  146  configured to pass through the central opening  133  on the dilator cap  130 . The central extension  146  may comprise one or more locking ridge  147  configured to pass through the central opening  133  and interact with a distal surface  138  of the dilator cap, holding the dilator handle  140  to the dilator cap  130 . In some embodiments, the distal surface of the dilator handle may comprise one or more additional spoke or wing extensions  148  configured to extend at least partially into the spoke or wings channels  134  when the dilator handle is connected to the dilator cap. In some embodiments, there are 2-4 additional spoke or wing extensions  148 . In some embodiments, each additional spoke or wing extension may connect to a surface of the central extension  146 . In some embodiments, each additional spoke or wing extension is configured such that a distal surface of each additional spoke or wing extension  148  is parallel with the distal surface  138  of the distal cap when the dilator handle is connected to the dilator cap. The central axis  149  of the dilator handle  140  may be configured to align with the central axis  135  of the dilator cap  130 . 
     The dilator handle may comprise one or more threads at the proximal end  142  for receiving one or more additional dilator components through the central lumen  144  along the central axis  135 . 
     A third aspect of the present disclosure is a drawn to a hemostatic valve assembly. Referring to  FIGS.  1 A and  1 B , a hemostatic valve assembly  200  is seen. The hemostatic valve assembly generally comprises a foam member  210  configured to secure an elastomeric member  220  at least partially within a housing  230  and provide structural support against a proximal end  221  of the elastomeric member  220 . 
     In some embodiments, the foam member  210  may contain a lubricant, such as a silicone oil, e.g., in the pores of the foam. 
     Referring to  FIG.  5   , it can be seen that the foam member  210  has a proximal surface  211  defining a first opening  215  extending along a longitudinal axis  213  from the proximal surface  211  to a distal surface  212  of the foam member  210 . In some embodiments, the first opening may be laser cut. 
     The foam member  210  may have at least one visibly identifiable portion  216  that is distinct from at least one other portion  217  on the proximal surface  211 . The at least one visible identifiable portion  216  may be a predetermined distance  218  from at least one edge of the first opening  215 . 
     In some embodiments, the predetermined distance is a distance between 1 mm and 8 mm, such as between 2 mm and 5 mm. 
     In some embodiments, the at least one visibly identifiable portion may comprise a portion that is visibly darker or lighter than a different portion of the foam. In some embodiments, the at least one visible identifiable portion may comprise one or more additional openings extending at least partially from the proximal surface towards the distal surface. In some embodiments, each of the one or more additional openings may have a diameter less than 0.5 mm. In some embodiments, the one or more additional openings may comprise between 2 and 4 additional openings. In some embodiments, the at least one visible identifiable portion may comprise one or more additional openings extending at least partially from the proximal surface towards the distal surface and a portion that is visibly darker or lighter than a different portion of the foam. 
     Referring to  FIG.  6 A , a simplified schematic of an alternative embodiment is seen, where the foam member  300  has an oval-shaped opening  301  and two additional openings  302 , each additional opening extending at least partially from the proximal surface towards the distal surface. In  FIG.  6 A , the two additional openings are shown as being equidistant from an edge of the opening  301 . 
     Referring to  FIG.  6 B , a simplified schematic of an alternative embodiment is seen, where the foam member  305  has an oval-shaped opening  306  which is surrounded at a distance by the at least one visibly identifiable portion  307  that is darker than a different portion  308  that is closer to the oval-shaped opening  306 . 
     Referring to  FIG.  6 C , a simplified schematic of an alternative embodiment is seen, where the foam member  315  has an circular opening  316  which is surrounded at different distances by the at least one visibly identifiable portions  312 ,  313 ,  314 , where each visibly identifiable portion comprises both additional openings  312  each extending at least partially from the proximal surface towards the distal surface, and each additional opening surrounded by a portion  313 ,  314  that is visibly lighter or darker (here, darker) than a different portion  315  closer to the opening  311 . Further, one of the visibly identifiable portions  314  is closer to an edge of the opening  311  than another visible identifiable portion  313 . 
     Referring to  FIG.  6 D , a simplified schematic of an alternative embodiment is seen, almost an inverse of  FIG.  6 B . Here, the foam member  329  has a circular opening  321  which is surrounded at a distance by the at least one visibly identifiable portion  322  that is lighter than a different portion  323  that is closer to the oval-shaped opening  321 . 
     In some embodiments, the foam may include more than one piece. In some embodiments, the pieces are adjacent to each other. 
     Referring to  FIG.  7   , in some embodiments, there may be cuts  410  (which may be, e.g., slits) in the foam member, extending at least partially, or in some cases entirely, through at least a portion of the foam member. In some embodiments, the cuts may be only in a single direction (e.g., only parallel to the x-axis). In some embodiments, the cuts may extend radially from a central axis. In some embodiments, there be at least one cut that is perpendicular to another cut. 
     In some embodiments, there may be one or more openings  420  extending through the foam and having a substantially circular cross-section. Such openings are helpful to guide physicians on where to puncture for single access. 
     In some embodiments, there may one or more openings  430  extending through the foam that do not have a circular cross-section. 
     In some embodiments, the foam surface facing outward may be divided into quadrants. In some embodiments, each quadrant of the foam may include one or more openings  420 . 
     Referring to  FIGS.  8 A and  8 B , a hub  450  can be seen, where the foam member  400  is shown in position within the hub. In some embodiments, a physician may puncture a valve  460  by inserting a needle through one of the openings  420 , and through valve  460 . In such embodiments, the one or more openings may be guides for aiding the physician in punction the valve. 
     While various aspects described herein relate to sheath designs that are particularly suitable for simultaneous use with multiple medical devices (e.g., via a single access technique), it should be appreciated that the presently disclosed sheath technology is not limited to uses with multiple medical devices, and that the presently disclosed sheath technology may provide advantages even when used with a single device (e.g., when used only to provide access for an intravascular blood pump or other suitable medical device). 
     Those skilled in the art will recognize or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. Such equivalents are intended to be encompassed by the following claims.