Patent Publication Number: US-2021177456-A1

Title: Window dressing for use with ultrasonic aid in venipuncture

Description:
FIELD OF THE INVENTION 
     The present invention relates generally to medical dressings. More particularly, the invention relates to a window dressing with an ultrasound transmissive layer that secures a catheter at an insertion site and provides transmissivity for an ultrasonic transducer. 
     BACKGROUND OF THE INVENTION 
     In many instances, it is necessary to insert a catheter into a patient&#39;s skin. When performing this procedure, it may be difficult to find a vein or the desired vein to insert the catheter. Accordingly, as an aid when inserting a catheter, medical clinicians (e.g., doctors, nurses, and other medical personnel) may use an ultrasonic transducer to visualize the vein. This allows the medical clinicians to find the desired vein, and then insert the catheter through the patient&#39;s skin and into the vein. The use of ultrasound to guide catheter placement reduces the number of access attempts and may reduce other complications as well. Ultrasound guidance can be used for placing central venous catheters as well as for placing peripheral venous catheters. 
     An example of using current dynamic real time ultrasonic transducer guidance involves placing a coat of ultrasound gel over a general area that a catheter is to be placed; locating a vein by ultrasound via a connected monitor; introducing a catheter into the desired vein by observing the needle piercing the vein by ultrasound visualization; removing the needle, leaving the catheter in place; removing ultrasound gel from the site; and placing a window dressing over the site. 
     While existing methods may provide advantages, there remain inherent shortcomings. Examples of such shortcomings may include bacteria being transmitted from the ultrasonic transducer or the ultrasound gel into the patient at the catheter insertion site from ultrasonic transducers that may not be cleaned properly. Existing procedures may include the use of a barrier to prevent or reduce intrusion of non-sterile ultrasound gel into the catheter insertion site. However, the non-sterile ultrasound gel used in such procedures is not contained and can contaminate the catheter insertion site and surrounding environment. Due to the risk of contamination and other deficiencies of known methods, there is a need for a sterilized, self-contained gel window dressing or a sterile, self-contained gel covering that can be placed on an ultrasonic transducer and a corresponding procedure for catheter placement. 
    
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
       Advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings. 
         FIG. 1  is an exploded view of a preferred embodiment of a window dressing according to the present invention. 
         FIG. 2  is a perspective view of the window dressing of  FIG. 1 . 
         FIG. 3  is a top, plan view of the window dressing of  FIG. 1 . 
         FIG. 4  is a bottom, plan view of the window dressing of  FIG. 1 . 
         FIG. 5  is a cross-sectional view of a window dressing with an ultrasound transmissive layer coextensive with a primary layer. 
         FIG. 6  is a cross-sectional view of a window dressing with an ultrasound transmissive layer and adhesive layer on a lower surface of a primary layer 
         FIG. 7  is a bottom, plan view of a window dressing with an ultrasound transmissive layer. 
         FIG. 8  is a bottom, plan view of a window dressing with an ultrasound transmissive layer with an alternating pattern of adhesive. 
         FIG. 9  is a bottom, plan view of a window dressing with an adhesive layer surrounding a window portion with an ultrasound transmissive layer. 
         FIG. 10  is a bottom, plan view of a window dressing with an adhesive layer surrounding a window and an alternating pattern of adhesive in an ultrasound transmissive layer. 
         FIG. 11  is a bottom, plan view of a window dressing with an adhesive layer surrounding an ultrasound transmissive layer deposited in a window. 
         FIG. 12  is a cross-sectional view of a window dressing with a pad. 
         FIG. 13  is a cross-sectional view of an ultrasonic transducer pad detached from an ultrasonic transducer. 
         FIG. 14  is a cross-sectional view of an ultrasonic transducer pad attached to an ultrasonic transducer. 
         FIG. 15  is a schematic representation of a method of using an ultrasonic transducer for aid in venipuncture in accordance with methods known in the prior art. 
         FIG. 16  is a schematic representation of a method of using an ultrasonic transducer for aid in venipuncture. 
         FIG. 17  is a schematic representation of a further method of using an ultrasonic transducer for aid in venipuncture. 
     
    
    
     While the invention is susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and will be described in detail herein. It should be understood, however, that the invention is not intended to be limited to the particular forms disclosed. Rather, the invention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. 
     DETAILED DESCRIPTION 
     Embodiments of the invention are now described in detail. Referring to the drawings, like numbers indicate like parts throughout the views. As used in the description herein and throughout the claims, the following terms take the meanings explicitly associated herein, unless the context clearly dictates otherwise: the meaning of “a,” “an,” and “the” includes plural reference, the meaning of “in” includes “in” and “on.” Relational terms such as first and second, top and bottom, forward and rearward, proximal and distal, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship, direction or order between such entities or actions. As used herein, unless specifically indicated otherwise, the terms lower, below or proximal refer to a direction toward the patient&#39;s skin on which the dressing is used, and the terms upper, above or distal refer to a direction away from the patient&#39;s skin on which the dressing is used. Reference may also be made to longitudinal and latitudinal directions in reference to the window dressing described herein. 
     In one embodiment, as illustrated in  FIGS. 1-4 , a window dressing  100  may be used to secure a catheter inserted at a catheter insertion site. Such insertion sites may include a PICC (“peripherally inserted central venous catheter”) insertion site, a jugular insertion site, a subclavian insertion site, a femoral insertion site, an implanted port insertion site, or any other similar insertion site. The window dressing  100  is capable of securing a variety of sizes, shapes, and types of catheters (single lumen, double lumen, triple, and quad lumen), infusion needles, and associated hubs, ports, and tubing. The window dressing  100  may provide protection against microbial ingress and site or patient systemic infection and may secure a catheter and associated hubs, ports, and tubing so that forces acting on the tubing and catheter do not peel the dressing from a patient&#39;s skin or cause the catheter to become dislodged. The window dressing  100 , specifically an ultrasound transmissive layer  114 , may also contain antimicrobial material that can provide additional protection against infection. 
     As further shown in  FIGS. 1-4 , a preferred embodiment of the window dressing  100  may comprise a primary layer  102  with an upper surface  104  and a lower surface  106 . The window dressing  100  may comprise additional layers distal of the primary layer  102 . These layers may include a transparent layer  108 , a support structure  110 , and one or more closure strips  112 . The dressing  100  may further comprise additional layers proximal of the primary layer  102 , including an ultrasound transmissive layer  114  and a release liner  116 . The primary layer  102  may comprise a window  118  and a slot  120 . The primary layer  102  may comprise a fabric material that may be a woven or nonwoven fabric. The fabric material may be formed from an appropriate material including manmade or naturally occurring fibers. Alternatively, the primary layer  102  may comprise a polymeric film. In various embodiments, the film or fabric layer may comprise plastic (PVC, polyethylene or polyurethane), latex, tape, cloth, paper or other materials. Still further, the primary layer  102  may comprise a combination of layers including fabrics or films or as well as coatings or additional supplemental materials. For example, the primary layer  102  may comprise materials having antimicrobial properties. The primary layer  102  as illustrated is generally square shaped with rounded corners; however, it is not limited to the illustrative shape. Accordingly, the primary layer  102  may come in many shapes, such as a circle, oval, rectangle, triangle, or any other shape. In addition, the size of the primary layer  102  may vary, such as a smaller size for a child and larger for an adult. 
     Window  118  may be positioned within a window portion  122  of the dressing  100 . The window  118  forms an opening that extends through the primary layer  102  forming a hole through the layer. The window  118  is positioned within the primary layer  102  such that the window  118  can be positioned around the insertion site when the dressing is applied to a patient. The window  118  may have a variety of shapes. For example, the window  118  may have a generally rectangular shape with rounded corners as illustrated in  FIGS. 1-3 . Alternatively, the window  118  may be domed shape. In further embodiments, the window  118  may be formed generally in the shape of a circle, half-circle, oval, square, triangle, polygon, crescent, or any other appropriate shape that allows the insertion site to be visible through the window  118 . 
     In one embodiment of the window dressing  100 , shown in  FIGS. 1-4 , a user positions the window  118  over the insertion site, and tubing (not shown) attached to the catheter is positioned beneath a securement portion  124  of the dressing  100 . In this manner, the catheter site is visible through the window  118 , and the tubing is secured to the patient&#39;s skin by the securement portion  124  of the dressing. 
     The securement portion  124  may comprise a slot  120 . The slot  120  may extend inwardly from an edge of the primary layer  102 . In a preferred embodiment, the slot  120  may be generally key shaped. Alternatively, the slot  120  may have a rectangular shape, U-shape, V-shape, or any other shape suitable to surround the catheter tubing. The slot  120  may be disposed in the securement portion  124  of the window dressing  100 . The slot  120  may provide a location for tubing to exit from underneath the window dressing  100  and may help secure the tubing in place. 
     One or more closure strips  112 , may be initially positioned on an upper or lower surface of the support structure  110 . Alternatively, the closure strips  112  may be coupled to either the top or bottom surface of any other layer of the window dressing  100 . The closure strips  112  may be detachably secured to the window dressing  100  with adhesive. These closure strips  112  may be detached and secured across the slot  120 , and over the tubing to provide for increased securement of the tubing against the window dressing  100  or the patient&#39;s skin. Additionally, the closure strips  112  may also be placed underneath the tubing to further secure a side edge of the window dressing  100  against the patient&#39;s skin. Closure strips  112  may be formed from the same material as the window dressing  100  and may be provided along with the window dressing  100 . Alternatively, the closure strips  112  may be a length of medical tape or another appropriate closure strip. 
     As illustrated in  FIGS. 1-3 , a transparent layer  108  may be positioned above the upper surface  104  of the primary layer  102 . Alternatively, the transparent layer  108  may be positioned below the lower surface  106  of the primary layer. The transparent layer  108  may comprise a transparent film. The transparent film may be a polyurethane film. In some embodiments, the transparent layer  108  may have semi-permeable characteristics. The transparent layer  108  may be a transmissive material so as to permit the sound waves from the ultrasonic transducer to penetrate the transparent layer  108  and ultrasound transmissive layer  114 . 
     In embodiments of the window dressing  100 , the transparent layer  108  may extend across all or a portion of the window portion  122  of the window dressing  100 . In a preferred embodiment, the transparent layer extends across the entire area of the window portion  122 , thereby securing the transparent layer  108  to the primary layer  102  and closing the window  118 . The transparent layer  108  may have generally the same shape as the window  118 . The transparent layer  108  may extend a distance beyond the periphery of the window  118  such that there is an area in which the transparent layer  108  overlaps with an upper surface  104  of the primary layer  102 . 
     In an alternate embodiment of the window dressing  100 , the transparent layer  108  extends across all or a portion of the securement portion  124  of the window dressing  100  in addition to extending across all or a portion of the window portion  122 . In addition, the transparent layer  108  may be coextensive with the primary layer  102 . Accordingly, in various embodiments, the transparent layer  108  covers the window  118  and is coupled to either the upper surface  104  or lower surface  106  of the primary layer  102 . 
     The dressing  100  may further comprise a support structure  110  coupled to the transparent layer  108  and/or the primary layer  102 . The support structure  110  may be a frame circumscribing the window  118  or in an alternative embodiment, may be coextensive with the primary layer  102 . As illustrated, for example, in  FIGS. 5-6 , the support structure  110  may comprise a top surface  126  and a bottom surface  128 . The support structure  110  may further comprise a support structure adhesive layer deposited on the bottom surface  128 . The adhesive may be any suitable medical grade adhesive and may be coextensive with the bottom surface  128 . Alternatively, the adhesive may extend across only a portion of the bottom surface  128  or may be applied in an alternating pattern of adhesive and non-adhesive areas. The support structure adhesive layer allows the support structure  110  to be adhered to the upper surface  104  of the primary layer  102  and/or the transparent layer  108 . Further, the support structure  110  may releasably adhere to the window dressing  100  and be removed once the window dressing  100  is placed on a patient&#39;s skin. 
     Embodiments of the support structure  110  may comprise a material that has a higher stiffness than the primary layer  102 . For example, the support structure  110  may comprise a polyester film. Preferably, the support structure  110  has a thickness between 0.005 and 0.100 inches, more preferably between 0.005 and 0.030, more preferably between 0.005 and 0.015, or yet more preferably having a thickness of 0.01 inches. The support structure  110  may be transparent or may have a color, texture or other property to visually distinguish the support structure  110  from the primary layer  102  of the window dressing  100 . For example, the support structure  110  may be transparent, translucent or opaque in combination with various levels of coloration. 
     Further, as shown in  FIGS. 1-3 , the support structure  110  may have tabs  130 . While a plurality of tabs may be used, it should be appreciated that embodiments using one tab are also contemplated. The tabs  130  provide a place that the user may grasp to pull the support structure  110  away from the transparent layer  108  and primary layer  102  after the window dressing  100  is attached to a patient. The tabs  130  can be visible protrusions, or alternatively, a lip that slightly overhangs the primary layer  102 . The tabs  130  may be a different color or texture to be distinguished from the support structure  110 . 
     Embodiments of the window dressing  100  may comprise an adhesive layer  132  (shown, e.g., in  FIG. 6 ) disposed on a lower, skin-facing surface of the dressing  100 . The adhesive layer  132  is exposed and able to adhere to a patient&#39;s skin once the release liner  116 , discussed below, has been discarded. The adhesive may comprise any suitable medical adhesive. For example, the adhesive may be an acrylate, including methacrylates and epoxy diacrylates. Alternatively, the adhesive may be a silicone based adhesive. In embodiments of the invention, the adhesive may be coextensive with the lower surface  106  of the primary layer  102 . 
     As can be seen in  FIG. 4 , the window dressing  100  may further comprise a release liner  116 . The release liner  116  may adhere or releasable adhere to a lower surface of the window dressing  100 , including to the lower surface  106  of the primary layer  102 , the adhesive layer  132 , ultrasound transmissive layer  114 , discussed below, or to some combination of these or other layers. The release liner  116  may extend across all or part of the proximal surface of the window dressing  100 . The release liner  116  may protect the adhesive layer  132  and/or ultrasound transmissive layer  114  from prematurely adhering to an undesired location and may be removed from the window dressing  100  prior to application onto the patient&#39;s skin in order to expose the adhesive layer  132  and/or ultrasound transmissive layer  114 . 
     Referring to  FIGS. 5-6 , an ultrasound transmissive layer  114  may be positioned between the lower surface  106  of the primary layer  102  and the release liner  116 . The ultrasound transmissive layer  114  acts as a layer that is transmissive to ultrasonic sound waves as used in diagnostic sonography or other medical ultrasound techniques. The ultrasound transmissive layer  114  may preferably comprise hydrogel, and the term hydrogel layer  114  is used interchangeably with ultrasound transmissive layer  114  herein. However, it should be understood that other transmissive gels, liquids, or other materials may be used and self-contained in the window dressing  100 . The ultrasound transmissive layer  114  may be in an even layer that is self-contained and deposited on a lower surface of a window portion  122 . Alternatively, it may only be found directly below the transparent layer  108  covering the window  118  or generally covering the window  118  but extending beyond the periphery of the window  118 . In a further alternative, the ultrasound transmissive layer  114  may be coextensive with the primary layer  102 . 
     The ultrasound transmissive layer  114  may come in a variety of thicknesses as would be understood by one of ordinary skill in the art. Preferably, the ultrasound transmissive layer  114  has a thickness between 0.02 and 5 millimeters, preferably between 0.2 and 4 millimeters, more preferably between 1 and 3 millimeters, or yet more preferably having a thickness of 1 millimeters. 
     The ultrasound transmissive layer  114  may have adhesive qualities, and thereby it may act as an adhesive to adhere the window dressing  100  to the patient. For example, the window dressing  100  may comprise the release liner  116  that releasably adheres to the ultrasound transmissive layer  114 . Once the release liner  116  is removed, as shown in  FIG. 7 , the ultrasound transmissive layer  114  can adhere to a patient, without the need of an adhesive layer  132 . 
     Alternatively, the ultrasound transmissive layer  114  may be used in conjunction with the adhesive layer  132 . In embodiments of the dressing, the adhesive may extend across only a portion of the lower surface  106  of the primary layer  102 . For example, as shown in  FIG. 8 , the ultrasound transmissive layer  114  may extend across a portion of the proximal surface of the window dressing  100 . Adhesive layer  132  may then be applied to a proximal surface of the dressing in an alternating pattern of adhesive  132 A.  FIG. 8  illustrates the adhesive applied in a dot pattern, but other shapes and patterns are contemplated. As shown, the adhesive pattern  132 A may be applied to areas covered by the ultrasound transmissive layer  114  and/or to areas of the primary layer  102  lower surface  106  that are not covered by the ultrasound transmissive layer  114 . Further, the ultrasound transmissive layer  114  may be deposited in areas that the adhesive, on the lower surface  106  of the primary layer  102 , is not found. For example, an adhesive layer on the lower surface  106  that circumscribes the window dressing  100  can have hydrogel deposited within the void created by the adhesive. 
     Alternatively, as illustrated in  FIG. 9 , the adhesive layer  132  may circumscribe the window portion  122  having the ultrasound transmissive layer  114 . In further embodiments, illustrated in  FIG. 10 , the adhesive layer  132  may circumscribe the window  118  as well as be inserted in an alternating pattern of adhesive  132 A in ultrasound transmissive areas within the window  118 . It will be appreciated that the adhesive layer  132  surrounding the window  118  may act as an additional barrier to prevent bacteria and other contaminates from reaching the insertion site. In further embodiments, illustrated in  FIG. 11 , the adhesive layer  132  may circumscribe the window  118  having the ultrasound transmissive layer  114 . 
     Having an ultrasound transmissive layer  114  in the window dressing  100 , removes the need for placing a non-sterile coat of ultrasound gel over the general area where the catheter is to be placed. The ultrasound transmissive layer  114  acts as a transmissive layer for the ultrasonic device. It will be appreciated that the ultrasound transmissive layer  114  may provide multiple advantages, including being self-contained and preventing a potential physical mess and contamination. The ultrasound transmissive layer  114  may further have anti-microbial material that can assist in providing a clean environment for the catheter site and ensure healing. Examples of anti-microbial material include but are not limited to silver, chlorhexidine, or polyhexamethylene biguanide. Further, the catheter insertion site may be completely covered by the ultrasound transmissive layer  114 , which helps prevent bacteria from entering the insertion site via the ultrasonic transducer or other non-sterile medical instruments. 
     Referring to  FIG. 12  and as discussed above, embodiments of the dressing  100  may comprise a pad  134  positioned above the upper surface  104  of the primary layer  102 . The pad  134  may be coupled to the support structure  110  and/or the transparent layer  108  and may extend across all or a portion of the window  118 . The pad  134  may be commensurate in size to the window portion  122 , or the pad  134  may be coextensive with the primary layer  102 . The pad  134  may comprise a top occlusive layer  136 , a middle liquid layer  138 , and a bottom occlusive layer  140 . The middle liquid layer  138  may be any liquid or gel that assists in the transmission of ultrasonic sound waves. The pad  134  may be used in conjunction with the ultrasound transmissive layer  114 . A removably attachable adhesive layer  142  may be deposited on a lower surface of the pad  134 . Further, the pad  134  may vary in materials and may have a thickness that is relatively thinner or thicker than the primary layer  102 . 
     As will be understood, the pad  134  may add an extra transmissive layer, with the ultrasound transmissive layer  114 , for transmissivity for an ultrasonic device to assist a user in finding the desired vein when inserting a catheter. The pad  134  may be removable by decoupling the pad  134 , with the removably attachable adhesive layer  142 , after the ultrasound has been performed. For example, once the user has found the correct vein and has inserted the catheter, the user then may discard the pad  134  by removing the pad  134  alone or by removing the support structure  110  with the pad  134  coupled thereto. The pad  134  may be provided coupled to the window dressing  100  or it may be provided as a separate component that is attached by the medical practitioner upon application of the window dressing  100 . It will also be appreciated that the liquid layer  138 , in the pad  134 , is self-contained. As discussed above with regard to the ultrasound transmissive layer  114 , having a self-contained pad  134  provides advantages over the prior art with respect to containment of potential liquid leakage and corresponding reduction of infection risk. 
     Further,  FIG. 12  illustrates embodiments of the window dressing  100  in a disassembled state prior to use. The transparent layer  108 , the support structure  110 , the closure strips  112 , and the pad  134  are positioned above the distal surface  104  of the primary layer  102 . The pad  134  further comprises a top occlusive layer  136 , a middle liquid layer  138 , and a bottom occlusive layer  140 , which together couples to the support structure  110  and/or the transparent layer  108 . The transparent layer  108  adheres to the upper surface  104  of the primary layer  102  at those points where the transparent layer  108  is in contact with the upper surface  104 . Embodiments of the transparent layer  108  are flexible, and the transparent layer  108  conforms to the surface of the primary layer  102 . 
     As shown in  FIGS. 13-14 , in further embodiments, an ultrasonic transducer pad  202  can be attached by a medical practitioner to an ultrasonic transducer  204 . The ultrasonic transducer pad  202  may come as part of a kit with the window dressing  100  or may be provided as a separate component. The ultrasonic transducer pad  202  may resemble the layers in the pad  134  illustrated in  FIG. 12 . The ultrasonic transducer pad  202  may comprise a release liner  206 , an adhesive layer  208 , a first occlusive layer  210 , a liquid layer  212 , and a second occlusive layer  214 . The liquid layer  212  may be any liquid or gel that assists in the transmission of ultrasonic sound waves. It will be understood that other layers may be utilized in the ultrasonic transducer pad  202 . The ultrasonic transducer pad  202  may be coextensive with an ultrasonic transducer attachment site  216  (as shown in  FIGS. 13-14 ). The release liner  206  is in a position to protect the adhesive layer  208  prior to coupling it to the ultrasonic transducer  204 . The adhesive layer  208  is positioned on an upper surface  209  of the first occlusive layer  210 . The adhesive layer  208  may extend across the upper surface  209  of the first occlusive layer  210  or may be applied in an alternating pattern of adhesive and non-adhesive areas. The first and second occlusive layers  210 ,  214  contain the liquid layer  212 , which allows for increased transmissivity to aid in finding a patient&#39;s vein. 
     It should be appreciated that the ultrasonic transducer pad  202  may be used without the window dressing  100 . For example, the ultrasonic transducer pad  202  may be used for other diagnostic sonography procedures beyond catheter placement. The ultrasonic transducer pad  202  may be used anytime it is desired to provide a self-contained object which can aid in transmissivity of ultrasound waves. The ultrasonic transducer pad  202  may be removed and replaced for additional procedures. It will be appreciated that the ultrasonic transducer pad  202  comprises a self-contained structure, which provides similar advantages to those discussed above with regard to the use of hydrogel in the window dressing  100 . 
     Currently known methods of placing a catheter with sonographic assistance require several steps devoted to uncontained gel management. As illustrated in  FIG. 15 , currently known methods require at least the following steps: (1) Sterilize the catheter insertion site with a conventional disinfectant such as Chlorhexidine Gluconate (CHG) or Isopropyl Alcohol (IPA)  302 ; (2) remove a release liner and place a window dressing having a support structure and closure strips on the site  304 ; (3) place an overlay on the site  306 ; (4) coat the top of the overlay with an ultrasound gel  308 , in the known method, the gel is squeezed from a tube of gel onto a top surface of the overlay; (5) position an ultrasound transducer in the gel coating the overlay  310 ; (6) insert and position the catheter with the aid of ultrasonic visualization  312 ; (7) remove the overlay, leaving a sterile dressing and catheter in place  314 ; (8) clean any gel that has migrated beyond the overlay  316 ; (9) remove the support structure from the dressing  318 ; (10) remove closure strips from support structure and place strips over the catheter tube to prevent movement of the catheter  320 ; and (11) sterilize the area as necessary due to any contamination by the uncontained gel  322 . 
     In contrast, methods using embodiments as disclosed herein do not require such steps. As illustrated in  FIG. 16 , methods employing disclosed embodiments require the following steps: (1) Sterilize the catheter insertion site with a conventional disinfectant such as Chlorhexidine Gluconate (CHG) or Isopropyl Alcohol (IPA)  402 ; (2) remove a release liner from the window dressing and place the window dressing at least partially on the site  404 ; (3) position an ultrasound transducer on top of the self-contained dressing that is contacting the skin  410 ; (4) insert and position the catheter with the aid of ultrasonic visualization  412 ; (5) remove the support structure from the dressing  418 ; and (6) remove closure strips from support structure and place strips over the catheter tube to prevent movement of the catheter  420 . 
     Alternatively, as illustrated in  FIG. 17 , a method may include additional steps incorporating a transducer pad ( 202 ) onto the transducer  204  to aid in transmissivity of ultrasound waves. In this method, including a step  510  in which a user may remove a release liner ( 206 ) from an ultrasonic transducer pad ( 202 ) and a step  511  in which a user couples the transducer pad ( 202 ) to an ultrasonic transducer attachment site ( 216 ). The user can then place the ultrasonic transducer ( 204 ) onto the window dressing ( 100 ) in step  410  and find the desired vein to insert a catheter in step  412 . Other steps may correspond to the steps set out above with regard to the method illustrated in  FIG. 16 . 
     While the present invention has been described with reference to one or more particular embodiments, those skilled in the art will recognize that many changes may be made thereto without departing from the spirit and scope of the present invention. Furthermore, components from one embodiment can be used in other non-exclusive embodiments. Each of these embodiments and obvious variations thereof is contemplated as falling within the spirit and scope of the invention.