Patent Publication Number: US-2022218955-A1

Title: Vascular Access Instrument Advancement Devices, Systems, and Methods

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     The present application claims priority to U.S. Provisional Application Ser. No. 63/137,049, entitled “Vascular Access Instrument Advancement Devices, Systems, and Methods” filed Jan. 13, 2021, the entire disclosure of which is hereby incorporated by reference in its&#39; entirety. 
    
    
     BACKGROUND 
     Catheters are commonly used to infuse fluids into vasculature of a patient. For example, catheters may be used for infusing normal saline solution, various medicaments, or total parenteral nutrition. Catheters may also be used for withdrawing blood from the patient. 
     A catheter may include an over-the-needle peripheral intravenous (“IV”) catheter. In this case, the catheter may be mounted over an introducer needle having a sharp distal tip. The catheter and the introducer needle may be assembled so that the distal tip of the introducer needle extends beyond the distal tip of the catheter with the bevel of the needle facing up away from skin of the patient. The catheter and introducer needle are generally inserted at a shallow angle through the skin into vasculature of the patient. 
     In order to verify proper placement of the introducer needle and/or the catheter in the blood vessel, a clinician generally confirms that there is “flashback” of blood in a flashback chamber. After placement of the introducer needle has been confirmed, the clinician may remove the introducer needle, leaving the catheter in place for future blood withdrawal or fluid infusion. 
     Overtime the catheter can become occluded at a tip of the catheter due to presence of fibrin sheath, thrombus, or vein walls or valves. Occlusions can limit functionality of the catheter for infusion and/or blood draw. The subject matter claimed herein is not limited to embodiments that solve any disadvantages or that operate only in environments such as those described above. Rather, this background is only provided to illustrate one example technology area where some implementations described herein may be practiced. 
     SUMMARY OF THE INVENTION 
     The present disclosure relates generally to an instrument advancement device, as well as related systems and methods. In some embodiments, the instrument advancement device may include a housing and an extension tube extending through the housing. In some embodiments, the extension tube may include a first lumen and a second lumen. It is understood that, in some embodiments, the extension tube may include one or more additional lumens to the first lumen and the second lumen. In some embodiments, a blood collection pathway may extend through the first lumen and/or one or more of the additional lumens. 
     In some embodiments, the instrument advancement device may include a wedge disposed within the housing and the second lumen of the extension tube. In some embodiments, the instrument advancement device may include a pair of opposing pinch members configured to pinch the extension tube. In some embodiments, the pair of opposing pinch members may be disposed within the housing and configured to move along the extension tube with the housing. In some embodiments, the pair of opposing pinch members may be disposed within the housing proximal to the wedge. 
     In some embodiments, the instrument advancement device may include an instrument, which may extend distally from the wedge. In some embodiments, the instrument may be disposed within the second lumen. In some embodiments, in response to moving the housing distally along the extension tube, the pair of opposing pinch members may push the wedge distally and the instrument may be advanced distally. In some embodiments, the instrument may include a vascular access instrument configured to advance distally through a catheter assembly and into vasculature of a patient. 
     In some embodiments, the instrument advancement device may include another pair of opposing pinch members configured to pinch the extension tube. In some embodiments, the other pair of opposing pinch members may be disposed within the housing distal to the wedge and configured to move along the extension tube with the housing. In some embodiments, in response to moving the housing proximally along the extension tube, the other pair of opposing pinch members may push the wedge proximally and the instrument may be retracted proximally. 
     In some embodiments, in response to movement of the housing along the extension tube, the opposing pinch members may rotate with respect to the housing and the extension tube. In some embodiments, an inner surface of the housing may include one or more bumps in contact with the pair of opposing pinch members. In some embodiments, the opposing pinch members may be fixed with respect to the housing. 
     In some embodiments, the instrument may include a guidewire. In some embodiments, the instrument advancement device may include a distal adapter. In some embodiments, a distal end of the extension tube may be coupled to the distal adapter. In some embodiments, the instrument advancement device may include a septum disposed within the distal adapter and configured to seal the second lumen and not the first lumen. In some embodiments, the instrument advancement device may include a septum disposed within the distal adapter and sealing the second lumen. In some embodiments, the instrument advancement device may include a blunt cannula, which may extend from the first lumen through the septum. 
     In some embodiments, the distal adapter may include a shaft and opposing lever locks. In some embodiments, the shaft may include a blunt cannula. In some embodiments, the instrument advancement device may include a cap disposed on the shaft. In some embodiments, a distal end of the cap may include an opening. 
     In some embodiments, the first lumen may extend through the extension tube. In some embodiments, the second lumen may extend through the extension tube. In some embodiments, a top surface of the extension tube may include a marking. In some embodiments, in response to the housing being aligned with the marking, the instrument may be advanced distally beyond a catheter tip a distance. In some embodiments, the marking may indicate the distance. In some embodiments, the top surface of the extension tube may include another marking. In some embodiments, in response to the housing being aligned with the other marking, the instrument may be aligned with the catheter tip. 
     In some embodiments, a top surface of the extension tube or distal adapter may include a marking. In some embodiments, the top surface of the instrument may include another marking. In some embodiments, in response to the other marking being aligned with the marking, the instrument may be advanced distally the distance beyond the catheter tip. 
     In some embodiments, the top surface of the extension tube or distal adapter may include a marking. In some embodiments, the top surface of the instrument may include another marking. In some embodiments, in response to the other marking being aligned with the marking, the instrument may be aligned with the catheter tip. 
     In some embodiments, the top surface of the distal adapter may include a marking. In some embodiments, the top surface of the instrument may include another marking. In some embodiments, in response to the other marking being moved from a proximal end of the marking to a distal end of the marking, the instrument may be advanced beyond the catheter tip a length of the marking. In some embodiments, the length of the marking may be 10 mm, 20 mm, 30 mm, 40 mm, 50 mm, or another length. In some embodiments, the length of the marking may be between 10 mm and 50 mm, inclusive, between 10 mm and 30 mm, inclusive, between 10 mm and 40 mm, inclusive, or between 20 mm and 40 mm, inclusive, for example. 
     In some embodiments, the instrument delivery device may include a proximal adapter coupled to a proximal end of the extension tube. In some embodiments, the proximal adapter may be configured to couple to a blood collection device. In some embodiments, the distal adapter and/or the proximal adapter may overmolded onto the extension tube, which may prevent fluid leakage. 
     It is to be understood that both the foregoing general description and the following detailed description are examples and explanatory and are not restrictive of the invention, as claimed. It should be understood that the various embodiments are not limited to the arrangements and instrumentality illustrated in the drawings. It should also be understood that the embodiments may be combined, or that other embodiments may be utilized and that structural changes, unless so claimed, may be made without departing from the scope of the various embodiments of the present invention. The following detailed description is, therefore, not to be taken in a limiting sense. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Example embodiments will be described and explained with additional specificity and detail through the use of the accompanying drawings in which: 
         FIG. 1  is an upper perspective view of an example instrument advancement device, according to some embodiments; 
         FIG. 2  is a cross-sectional view of an example distal end of the instrument advancement device, according to some embodiments; 
         FIG. 3  is a cross-sectional view of another example distal end of the instrument advancement device, according to some embodiments; 
         FIG. 4  is a cross-sectional view of an example housing of the instrument advancement device, illustrating an example extension tube extending therethrough, according to some embodiments; 
         FIG. 5A  is an upper perspective view of an example piece of the housing, according to some embodiments; 
         FIG. 5B  is an upper perspective view of another example piece of the housing configured to couple to the piece of the housing of  FIG. 5A , according to some embodiments; 
         FIG. 6A  is a top view of an example cap coupled to the instrument advancement device, according to some embodiments; 
         FIG. 6B  is an upper perspective view of the cap, according to some embodiments; 
         FIG. 6C  is another upper perspective view of the cap, illustrating an example opening, according to some embodiments; 
         FIG. 7  is a cross-sectional view of an example proximal end of the instrument advancement device, according to some embodiments; 
         FIG. 8A  is a top view of an example distal adapter that includes an example marking, according to some embodiments; 
         FIG. 8B  is an upper perspective view of an example instrument, illustrating another example marking, according to some embodiments; 
         FIG. 8C  is an upper perspective view of a portion of the instrument advancement device, illustrating example markings, according to some embodiments; and 
         FIG. 8D  is an upper perspective view of the instrument advanced distally beyond a catheter tip of an example catheter, according to some embodiments. 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Referring now to  FIG. 1 , an instrument advancement device  10  is illustrated, according to some embodiments. In some embodiments, the instrument advancement device  10  may include a housing  12  and an extension tube  14  extending through the housing  12 . In some embodiments, the extension tube  14  may be rigid, semi-rigid, or flexible. In some embodiments, the extension tube  14  may include a coextruded guidewire to add stiffness to the extension tube  14 . In some embodiments, the extension tube  14  may include a multi-lumen extension tube. 
     In some embodiments, the instrument advancement device  10  may include an instrument  16 , which may include a guidewire, a tube, or another suitable instrument. In some embodiments, the instrument  16  may be colored to increase visibility. In some embodiments, the guidewire may be constructed of metal or another suitable material. In these and other embodiments, the instrument  16  may be lubricated or coated to ease advancement. In some embodiments, the tube may be soft or stiff. In some embodiments, the tube may create a closed path for blood flow and/or reduce contamination of the blood due to drug adsorption in a catheter assembly. 
     In some embodiments, the instrument  16  may include a guidewire, which may include a spring or coil. In some embodiments, the spring or coil may include varying pitches along a length of the spring or coil. For example, a pitch of the spring or coil upstream from or proximal to a catheter tip may be larger to facilitate more blood flow and increase flow rate, and a pitch of the spring or coil near the catheter tip may be smaller to prevent blood clots from entering the catheter tip, while still allowing blood to flow through it. In some embodiments, the guidewire may include a rod, which may extend through a center portion of the spring or coil. In some embodiments, the guidewire may include the rod and may not include the spring or coil. 
     Over time a catheter can become occluded at the catheter tip due to presence of fibrin sheath, thrombus, or vein walls or valves. In some embodiments, the instrument  16  may be configured to extend into and/or through the catheter assembly to push through and/or disrupt an occlusion of the catheter. In some embodiments, the instrument  16  may overcome thrombus and fibrin sheath in or around the catheter assembly or in the vein that might otherwise prevent blood draw. In some embodiments, the instrument advancement device  10  may reduce trauma to the vasculature while also facilitating fluid delivery, blood collection, patient or device monitoring, or other clinical needs. In some embodiments, the instrument advancement device  10  may decrease hemolysis and reduce blood exposure. In some embodiments, the instrument  16  may include a vascular access instrument configured to advance distally through the catheter assembly and into the vasculature of the patient. 
     In some embodiments, a distal end of the instrument advancement device  10  may include a distal adapter  18  or another suitable connector. In some embodiments, the distal adapter  18  may be configured to couple to the catheter assembly, which may be existing or already dwelling within the vasculature of the patient. In some embodiments, the catheter assembly may include a catheter adapter, which may include a distal end, a proximal end, and a lumen extending through the distal end of the catheter adapter and the proximal end of the catheter adapter. In some embodiments, the catheter may extend from the distal end of the catheter adapter. In some embodiments, the catheter may include a peripheral intravenous catheter, a midline catheter, or a peripherally inserted central catheter. In some embodiments, the catheter assembly may include an introducer needle, which may extend through the catheter and facilitate piercing of skin and the vasculature to insert the catheter into the patient. In some embodiments, the introducer needle may be removed from the catheter assembly prior to coupling of the instrument advancement device  10  to the catheter assembly. 
     In some embodiments, the catheter assembly may be straight. In other embodiments, the catheter assembly may be integrated, having an extension tube that is integrated with the catheter adapter. In some embodiments, the catheter assembly may include an extension set, which may include the extension tube extending from and integrated with a side port of the catheter adapter. In some embodiments, the distal adapter  18  may be configured to couple to a portion of the catheter assembly, such as the proximal end of the catheter adapter and/or a needleless access connector. In some embodiments, the needleless access connector may be coupled to a proximal end, a T-connector, or another portion of the extension set. In some embodiments, the needleless access connector may be permanently connected, such as, for example, via adhesive, to the distal adapter  18  to prevent intentional or unintentional removal by a user. 
     In some embodiments, a distal end of the extension tube  14  may be coupled to the distal adapter  18 . In some embodiments, a proximal end of the extension tube  14  may be coupled to a proximal adapter  20 , which may include another distal adapter or another suitable connector. In some embodiments, the proximal adapter  20  may be configured to couple to a blood collection device. In some embodiments, the blood collection device may include a syringe, a BD VACUTAINER® one-use holder (available from Becton, Dickinson and Company of Franklin Lakes, N.J.), a BD VACUTAINER® LUER-LOK™ access device (also available from Becton, Dickinson and Company of Franklin Lakes, N.J.), or another suitable blood collection device, which may provide suction. 
     In some embodiments, the instrument  16  may be advanced prior to or during infusion or blood draw. In some embodiments, after completing a blood draw or infusion and before uncoupling the instrument advancement device  10  from the catheter assembly, the user may retract the instrument by moving the housing  12  backward or proximally. Thus, in some embodiments, a risk of exposure of the user to blood may be decreased. 
     Referring now to  FIG. 2 , in some embodiments, the extension tube  14  may include a first lumen  22  and a second lumen  24 , which may be separate from the first lumen  22  along an entire length of the extension tube  14 . In some embodiments, a blood collection pathway may extend through the first lumen  22 . In some embodiments, the instrument  16  may be disposed within the second lumen  24 . In some embodiments, a diameter of the second lumen  24  may be larger than a diameter of the first lumen  22 . In some embodiments, the diameter and/or a length of the first lumen  22  may be selected based on a desired flow rate and/or to reduce hemolysis. 
     In some embodiments, in response to moving the housing  12  distally along the extension tube  14 , the instrument  16  may be advanced distally within the second lumen  24 . In some embodiments, in response to moving the housing  12  proximally along the extension tube  14 , the instrument  16  may be retracted proximally within the second lumen  24 . 
     In some embodiments, the instrument advancement device  10  may include a septum  26  disposed within the distal adapter  18  and configured to seal the second lumen  24  or prevent blood flow into the second lumen  24 . In these and other embodiments, the septum  26  may not seal the first lumen  22  such that blood may flow proximally along a fluid pathway  28  from the distal adapter  18  through the first lumen  22  for blood collection. In some embodiments, the septum  26  may be elastomeric. 
     In some embodiments, a distal end of the instrument  16  may be disposed proximal to a distal end of the distal adapter  18  when the housing  12  is fully retracted in a proximal direction. In some embodiments, the distal end of the instrument  16  may be disposed proximal to the septum  26  when the housing  12  is fully retracted in the proximal direction and/or the instrument  16  may be sealed within the extension tube  14 . 
     In some embodiments, the instrument advancement device  10  may include a cannula  30 , which may connect a distal end of the first lumen  22  and the distal adapter  18 . In some embodiments, the cannula  30  may be blunt. In some embodiments, the fluid pathway  28  may extend through the cannula  30 , which may prevent blood leakage. In some embodiments, the cannula  30  may be constructed of steel, plastic, metal, or another suitable material. In some embodiments, the cannula  30  may be coupled to the distal adapter  18  or monolithically formed with the distal adapter  18  as a single unit. In some embodiments, the septum  26  may be concentric with the second lumen  24  or offset slightly to obtain adequate wall thicknesses. 
     In some embodiments, the distal adapter  18  may include a shaft  38  and opposing lever locks  40 . In some embodiments, the lever locks  40  may facilitate coupling to the needleless access connector. In some embodiments, the shaft  38  may be lubricated with a lubricant, which may reduce a force of insertion into the catheter assembly. In some embodiments, the male distal adapter may include a male luer, a male luer lock, a male slip luer, a luer, or another suitable connector. 
     Referring now to  FIG. 3 , in some embodiments, the septum  26  may extend across a width of an inner lumen of the distal adapter  18 . In some embodiments, the septum  26  may seal the second lumen  24  or prevent blood flow into the second lumen  24 . In some embodiments, the cannula  30  may extend from the first lumen  22  through the septum  26  to allow fluid flow therethrough. 
     Referring now to  FIG. 4 , in some embodiments, the instrument advancement device  10  may include a wedge  32  disposed within the housing  12  and the second lumen  24  of the extension tube  14 . In some embodiments, the instrument advancement device  10  may include a pair of opposing pinch members  34  configured to pinch the extension tube  14 . In some embodiments, the pair of opposing pinch members  34   a,b  may be disposed within the housing  12  proximal to the wedge  32  and configured to move along the extension tube  14  with the housing  12 . 
     In some embodiments, the instrument  16  may extend distally from the wedge  32 . In some embodiments, the instrument  16  may be disposed within the second lumen  24 . In some embodiments, in response to moving the housing  12  distally along the extension tube  14 , the pair of opposing pinch members  34   a,b  may push the wedge  32  distally, and the instrument  16  may be advanced distally. 
     In some embodiments, the instrument advancement device  10  may include another pair of opposing pinch members  34   c,d  configured to pinch the extension tube  14 . In some embodiments, the other pair of opposing pinch members  34   c,d  may be disposed within the housing distal to the wedge  32  and configured to move along the extension tube  14  with the housing  12 . In some embodiments, in response to moving the housing  12  proximally along the extension tube  14 , the pair of opposing pinch members  34   c,d  may push the wedge  32  proximally and the instrument  16  may be retracted proximally. 
     The pair of opposing pinch members  34   a,b  and the other pair of opposing pinch members  34   c,d  may be referred to collectively in the present disclosure as “opposing pinch members  34 .” In some embodiments, in response to movement of the housing  12  along the extension tube  14 , the opposing pinch members  34  may rotate with respect to the housing  12  and the extension tube  14 . In some embodiments, in response to movement of the housing  12  along the extension tube  14 , the opposing pinch members  34  may rotate with respect to the housing  12  and the extension tube  14 , which may rotate the instrument  16 . In some embodiments, an inner surface of the housing  12  may include one or more bumps  36  in contact with the opposing pinch members  34 , which may reduce friction as the opposing pinch members  34  rotate. In some embodiments, the wedge  32  and/or the opposing pinch members  34  may be lubricated with a lubricant, which may reduce friction. 
     In some embodiments, the opposing pinch members  34  may be constructed of plastic, metal, or another suitable material. In some embodiments, the opposing pinch members  34  may include spherical balls, ball bearings, wheels, or cylinders, which may be configured to rotate with respect to the housing  12 . In some embodiments, the opposing pinch members  34  may include the wheels, which may be smooth or include feet along their edges. In these embodiments, lubricant may be applied to axels of the wheels to reduce friction. In some embodiments, the opposing pinch members  34  may be fixed with respect to the housing  12 . For example, the opposing pinch members  34  may be molded into the housing  12 . 
     In some embodiments, a number of the opposing pinch members  34  may vary based on a shape of the wedge  32 . In some embodiments, the instrument advancement device  10  may include the pair of opposing pinch members  34   a,b  and the other pair of opposing pinch members  34   c,d  in response to the shape of the wedge  32  being cylindrical, for example. In some embodiments, the instrument advancement device  10  may include a single pair of the opposing pinch members  34 , such as the pair of the opposing pinch members  34   a,b , in response to the wedge  12  including a dog bone shape, and the single pair may be disposed in a middle or depression of the dog bone shape. 
     Referring now to  FIG. 5A-5B , in some embodiments, the housing  12  may include an aperture  41  extending therethrough and configured to receive the extension tube  14 . In some embodiments, the inner surface of the housing  12  may include one or more protrusions  42 , which may contact the extension tube  14  to reduce friction between the extension tube  14  and the housing  12  as the housing  12  moves along the extension tube  14 . In some embodiments, the housing  12  may include multiple pieces  44   a,b , which may be coupled together via pegs  45  or any other suitable mechanism. In other embodiments, the housing  12  may be monolithically formed as a single unit. 
     In some embodiments, the housing  12  may include multiple cutouts  46 , which may include the bumps  36 . In these and other embodiments, the opposing pinch members  34  may include the spherical balls. In some embodiments, the cutouts  46  may be generally spherical and/or may extend outwardly from the aperture  41 . In some embodiments, halves of the cutouts  46  illustrated in the multiple pieces  44   a,b  may be joined together to form the cutouts  46 . 
     In some embodiments, the housing  12  may be rigid or semi-rigid to facilitate gripping and/or one-handed advancement by the user. In some embodiments, the housing  12  may include one or more grip features or a shape to facilitate gripping by the user. In some embodiments, the grip features may include one or more of ridges, indents, and tabs on a top of the housing  12  and/or one or more sides of the housing  12 . In some embodiments, the shape of the housing  12  may include a square, cylinder, dog bone, or another suitable shape. In some embodiments, the shape of the housing  12  and/or the grip features may facilitate the user advancing and/or retracting the instrument  16  without contacting the instrument, thereby decreasing a risk of contamination and/or infection. In some embodiments, the housing  12  may include one or more textured surfaces to facilitate gripping by the user. 
     Referring now to  FIG. 6A-6C , in some embodiments, the instrument advancement device  10  may include a cap  48  disposed on the shaft  38 . In some embodiments, the cap  48  may include one or more grip features along edges of the cap  48  to ease removal from the shaft  38 , which may be blunt. In some embodiments, the cap  48  may be filled in at the distal end, as illustrated, for example, in  FIG. 6B , which may prevent the instrument from prematurely pushing past a tip of the shaft  38  during shipping or priming of the instrument advancement device  10 . 
     In some embodiments, a distal end of the cap  48  may include an opening  50 , as illustrated, for example, in  FIG. 6C . In some embodiments, the opening  50  may reduce material, cost, and prevent damage to the instrument  16  if the user neglects to take off the cap  48  prior to advancement. 
     Referring now to  FIG. 7 , in some embodiments, the proximal end of the extension tube  14  may be coupled to the proximal adapter  20 , which may include a female luer, a female luer lock, a female slip luer, a luer, or another suitable connector. In some embodiments, the proximal adapter  20  may be configured to couple to the blood collection device. In some embodiments, the first lumen  22  may extend through the extension tube  14 . In some embodiments, the second lumen  24  may extend through the extension tube  14 . 
     In some embodiments, the distal adapter  18  may not include a septum, such as the septum  26  described with respect to  FIGS. 2-3 . In these and other embodiments, the proximal adapter  20  may block a proximal end of the extension tube  14  to prevent blood leakage through the proximal adapter  20 , as illustrated, for example, in  FIG. 7 . In some embodiments, sealing may be accomplished by over molding the proximal adapter  20  and/or the distal adapter  18  on either end of the extension tube  14  to form a seal around the instrument  16 . 
     In some embodiments, the instrument advancement device  10  may include a cannula  52 , which may connect a proximal end of the first lumen  22  and the proximal adapter  20 , to prevent blood leakage. In some embodiments, the cannula  52  may be blunt. In some embodiments, the fluid pathway  28  may extend through the cannula  52 . In some embodiments, a fluid path, such as a length and/or diameter, through one or more of the following may be selected or optimized to increase a flow rate and decrease a risk of hemolysis: the distal adapter  18 , the proximal adapter  20 , the cannula  52 , the cannula  30 , and the extension tube  14 . 
     Referring now to  FIGS. 8A-8B , in some embodiments, a top surface of the distal adapter  18  may include a marking  54 , which may be visible to the user during use. In some embodiments, a top surface of the instrument  16  may include another marking  56 . In some embodiments, the distal adapter  18  may be transparent, which may allow the user to see the other marking  56  through the distal adapter  18 . In some embodiments, the marking  54  and/or the other marking  56  may instruct the user about advancement of the instrument  16 . In some embodiments, in response to the other marking  56  being moved from a proximal end of the marking  54  to a distal end of the marking  54 , the instrument  16  may be advanced beyond the catheter tip a distance equal to a length of the marking  54 . In some embodiments, the length of the marking  54  may be 30 mm or another suitable length. 
     In some embodiments, the marking  54  and/or the other marking  56  may be molded in, etched on, lasered, painted, or provided in another suitable manner. In some embodiments, the marking  54  may include a line that is parallel to a longitudinal axis of the instrument advancement device  10 . Additionally, in some embodiments, the marking  54  may include a number and/or units corresponding to the length of marking  54 . In some embodiments, the other marking  56  may include a line, which may be perpendicular to the longitudinal axis of the instrument advancement device  10 , or another suitable marking. In some embodiments, the instrument  16  may be shaded or frosted, which may facilitate visibility of the instrument  16  by the user. In some embodiments, the distal adapter  18  may include a bond pocket  57  in which the distal end of the extension tube  14  may be secured and/or adhered. 
     Referring now to  FIG. 8C , in some embodiments, a top surface of the extension tube may include one or more markings, which may be visible to the user during use. In some embodiments, the markings may be molded in, etched on, lasered, painted, or provided in another suitable manner. In some embodiments, the markings may instruct the user about advancement of the instrument  16 . In some embodiments, the top surface of the extension tube  14  may include the marking  54  described with respect to  FIG. 8A . In some embodiments, in response to the other marking  56  of the instrument (see, for example,  FIG. 8B ) being moved from a proximal end of the marking  54  to a distal end of the marking  54 , the instrument  16  may be advanced beyond the catheter tip a distance equal to a length of the marking  54 . In some embodiments, the length of the marking  54  may be 30 mm or another suitable length. 
     In some embodiments, the markings on the top surface of the extension tube  14  may include a marking  58  and/or a marking  60 . In some embodiments, in response to the housing  12  or the marking  56  being aligned with the marking  58 , the instrument  16  may be advanced distally beyond the catheter tip  64  of a catheter  62  a distance (see, for example,  FIG. 8D ). In some embodiments, the marking  58  may indicate the distance, such as, for example 30 mm. In further detail, in some embodiments, the marking  58  may include a number and/or units corresponding to the distance. 
     In some embodiments, in response to the housing  12  or the marking  56  being aligned with the marking  60 , the instrument  16  may be aligned with the catheter tip  64 . In some embodiments, the marking  58  and/or the marking  60  may include lines, which may be perpendicular to the longitudinal axis of the instrument advancement device  10 , or other suitable markings. In some embodiments, the marking  60  may include a number and/or units corresponding to a position of a distal end of the instrument  16 . 
     In some embodiments, the extension tube  14  may be transparent to facilitate visibility of the instrument  16  therein. In some embodiments, the marking  58  and/or the marking  60  may be disposed on the distal adapter  18 , which may be transparent. Referring now to  FIG. 8D , the instrument  16  may be disposed distal to the catheter tip  64 . In some embodiments, the instrument  16  may be advanced distally beyond the catheter tip  64  in response to the housing  12  being advanced in the distal direction. 
     All examples and conditional language recited herein are intended for pedagogical objects to aid the reader in understanding the invention and the concepts contributed by the inventor to furthering the art and are to be construed as being without limitation to such specifically recited examples and conditions. Although embodiments of the present inventions have been described in detail, it should be understood that the various changes, substitutions, and alterations could be made hereto without departing from the spirit and scope of the invention.