Patent Publication Number: US-2021178059-A1

Title: Single Step Removal of Cannula Guard and Adhesive Liner in Medical Device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is a division of U.S. patent application Ser. No. 13/784,721, filed on Mar. 4, 2013, the disclosure of which is incorporated herein by reference in its entirety. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates to medical devices, and more particularly, to medical devices with a cannula and an adhesive for securing the device to a patient&#39;s skin. 
     BACKGROUND OF THE INVENTION 
     Medical devices that are intended to deliver medicament or monitor patient conditions over an extended period of time are often designed to be worn by the patient. Many of these devices have a medical pressure sensitive adhesive to secure the device to the patient&#39;s skin as well as a cannula that is inserted through the patient&#39;s skin for delivering the medicament. 
     Insulin infusion sets designed for connection to insulin pumps are examples of these types of medical devices. Infusion pumps offer the advantages of continuous infusion of insulin, precision dosing, and programmable delivery schedules. Together, these advantages result in more accurate blood glucose control. With infusion sets, the types and sizes of the cannula may vary, but generally, the cannula is a thin, flexible tube. In some uses, however, it may be larger and/or rigid, for example, a rigid, hollow, metal needle. For insertion of a flexible cannula, a rigid introducer needle may be used. 
     One type of conventional infusion set is sold as the Quick-Set® infusion set by Medtronic. In such devices, the infusion set is connected to a pump via a tubing set, and a separate insertion device inserts and/or attaches the cannula assembly into/to a user via an introducer needle provided as part of the infusion set. The infusion set and insertion device can also be combined, as in the Mio® infusion set sold by Medtronic, which is an “all-in-one” design that combines the infusion set and insertion device into one unit. 
     Another type of insulin infusion device, known as a “patch pump,” has recently become available. Unlike a conventional infusion pump, a patch pump is an integrated device that combines most or all of the fluid components in a single housing that is adhesively attached to an infusion site, and does not require the use of a separate infusion (tubing) set. A patch pump adheres to the skin, contains insulin (or other medication), and delivers the drug over a period of time via an integrated subcutaneous mini-catheter. Some patch pumps communicate with a separate controller device wirelessly (such as one sold under the brand name OmniPod®), while others are completely self-contained. 
     On-body continuous glucose monitoring (CGM) devices are also examples of medical devices with an insertable cannula and an adhesive to secure the device to the patient&#39;s skin. 
     To protect the cannula and/or introducer needle in the packaging and prior to insertion (as well as protect against accidental needle-stick injuries), conventional devices often include a cannula guard (sometimes referred to as a needle guard) that is removed prior to use. These needle guards, however, are often very small and may be difficult to grasp, particularly for people with impaired dexterity. To remove such needle guards, patients pull and/or twist the needle guard, and the axial force required to remove such needle guards may vary widely, for example, based on manufacturing tolerances. 
     The medical pressure sensitive adhesive (sticky layer) is typically covered by a release liner that has a silicone covering on one side to that permits the liner to release from the adhesive. Many adhesive release liners are divided into two or more pieces by slits, each of which should be removed prior to insertion of the device into a patient&#39;s skin. For people with impaired dexterity, these pieces may be difficult to grasp and remove. 
     Currently, patients have to remove the needle guard and peel off adhesive release liner in separate steps before they either directly apply the device onto their body or assemble the medical device into an insertion device. For example, with a conventional insulin infusion set, a user first peels off the adhesive liner(s), then assembles the infusion set into the inserter. Subsequently, the user pushes the needle guard inside the inserter to engage the set with the inserter and to load the inserter (for example, to load the spring). Finally, the user twists or pulls off the needle guard. During this process, exposed adhesive can catch on the user&#39;s finger or the inner wall of the inserter, potentially requiring the use of a new infusion set. 
     SUMMARY OF EMBODIMENTS OF THE INVENTION 
     Accordingly, it is an aspect of the present invention to provide a medical device in which the adhesive liner and the cannula guard can be removed in a single step. 
     The foregoing and/or other aspects of the present invention are achieved by providing a medical device, including a body and a cannula extending from the body, for insertion into a patient&#39;s skin. The medical device also includes a guard covering the cannula, an adhesive for securing the medical device to the patient&#39;s skin, and an adhesive liner covering the adhesive. The guard is connected to the adhesive liner to enable conjoint and at least partial removal of the guard and the adhesive liner. 
     The foregoing and/or other aspects of the present invention are also achieved by providing a method of preparing a medical device for insertion into a patient&#39;s skin. The method includes conjointly and at least partially removing a cannula guard and an adhesive liner from the medical device. 
     The foregoing and/or other aspects of the present invention are also achieved by providing a method of preparing a medical device for insertion into a patient&#39;s skin. The method includes providing a guard for covering an insertable cannula of the medical device, and providing an adhesive liner for protecting an adhesive surface and/or adhesive pad of the medical device. The method also includes connecting the needle guard to the adhesive liner so that removal of one of the guard and the adhesive liner from the medical device also at least partially removes the remaining one of the guard and the adhesive liner. 
     The foregoing and/or other aspects of the present invention are also achieved by providing a protector for a medical device, including a guard for covering a cannula of the medical device, and an adhesive liner for covering an adhesive for securing the medical device to a patient&#39;s skin. The guard is connected to the adhesive liner to enable conjoint and at least partial removal of the guard and the adhesive liner. 
     The foregoing and/or other aspects of the present invention are also achieved by providing a method of preparing a medical device for insertion into a patient&#39;s skin. The method includes installing the medical device into an insertion device, and subsequent to such installation, conjointly and at least partially removing a cannula guard and an adhesive liner from the medical device. 
     Additional and/or other aspects and advantages of the present invention will be set forth in the description that follows, or will be apparent from the description, or may be learned by practice of the invention. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The above and/or other aspects and advantages of embodiments of the invention will be more readily appreciated from the following detailed description, taken in conjunction with the accompanying drawings, in which: 
         FIG. 1  is a perspective front view of a medical device in accordance with an embodiment of the present invention; 
         FIG. 2  is a cross-sectional view of the device of  FIG. 1 ; 
         FIG. 3  is a bottom perspective view of a protector in accordance with an embodiment of the present invention; 
         FIGS. 4-6  illustrate removal of the protector of  FIG. 3 ; and 
         FIGS. 7-15  illustrate additional protectors in accordance with additional embodiments of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF EMBODIMENTS OF THE PRESENT INVENTION 
     Reference will now be made in detail to embodiments of the present invention, which are illustrated in the accompanying drawings, wherein like reference numerals refer to like elements throughout. The embodiments described herein exemplify, but do not limit, the present invention by referring to the drawings. As will be understood by one skilled in the art, terms such as up, down, bottom, and top are relative, and are employed to aid illustration, but are not limiting. 
       FIG. 1  is a perspective front view of a medical device  100  in accordance with an embodiment of the present invention, and  FIG. 2  is a cross-sectional view of the device  100 . The device  100  includes a base  104  with an adhesive pad  108  secured to its distal side for securing the device  100  to a patient&#39;s skin. An insertable cannula  112  depends from the distal side of the base  104 . According to one embodiment, the cannula  112  is a flexible cannula  112  and the device  100  includes an introducer needle  116  with a user interface or handle  120  for removing the introducer needle  116  from the base  104 . One skilled in the art will appreciate, however, that other cannulas can be used without departing from the scope of the present invention. The medical device  100  also includes a protector  140 . 
     As shown in  FIGS. 1-3 , according to one embodiment, the protector  140  includes a guard  144  covering the cannula  112  and the introducer needle  116 , and an adhesive liner  148  covering the adhesive pad  108  and connected to the guard  144 . The nature of the connection between the adhesive liner  148  and the guard  144  is such that removing one will also at least partially remove the other. In other words, the adhesive liner  148  and the guard  144  are operatively interrelated. Put another way, the adhesive liner  148  and the guard  144  are coupled. For example, according to one embodiment, the adhesive liner  148  and the guard  144  are joined directly to each other, for example, by an adhesive, such as a liquid instant adhesive. According to another embodiment, another element or elements can intercede between, but mechanically join the adhesive liner  148  and the guard  144 . For example, double-sided tape can be used to join the adhesive liner  148  and the guard  144 . As another example, a strip of paper, plastic, metal, string, or other material can be connected at one end to the adhesive liner  148  and be connected at another end to the guard  144 . According to one embodiment, the strip is flexible. According to an alternative embodiment, the strip is rigid. 
     The guard  144  includes a guarding portion  152  for covering the cannula  112  and the introducer needle  116 , and a connecting portion  156  for connecting with the adhesive liner  148 . As shown in  FIG. 3 , the guarding portion  152  is open at its distal end. According to another embodiment (shown in  FIG. 8 , for example), the guarding portion is enclosed at its distal end. 
     According to one embodiment, the connecting portion  156  includes an arm  160  extending from the guarding portion  152 . As shown in  FIG. 3 , the connecting portion  156  includes a plurality of arms  160 , specifically, four arms  160 . It will be understood, that the number of arms can be greater or lesser without departing from the scope of the present invention. The arms  160  are substantially straight, and are cantilevered from the guarding portion  152 . 
     In addition, as shown in  FIG. 3 , the liner  148  has a plurality of slits  164  corresponding to the plurality of arms  160 . One skilled in the art will appreciate that that the liner  148  can have a number of slits that is different from the number of arms without departing from the scope of the present invention. Preferably, the arms  160  are connected to the liner  148  at or adjacent to the respective slits  164 , although the liner can be connected to the connecting portion  156  at another location. Additionally, it is preferable that the shapes of the slits  164  correspond to the shapes of the arms  160 . For example, as shown in  FIG. 3 , both the arms  160  and the slits  164  are substantially straight. It will be appreciated by one skilled in the art, however, that without departing from the scope of the present invention, a slit can have a different shape than an arm. It will also be appreciated that the shapes of arms and slits can be different among the respective pluralities. In other words, some slits can be straight while others are not, and some arms can be straight while others are not. It will also be appreciated that, without departing from the scope of the present invention, a liner may not include a slit. 
     In operation, to remove the protector  140 , the user grasps the protector  140  and pulls axially (i.e., distally), or both rotates and pulls axially, thereby conjointly removing the connected guard  140  and adhesive liner  148 . Because the guard  140  and the adhesive liner  148  are joined, removal of either the liner  148  or the guard  140  is conjoint with at least partial removal of the other. Put another way, according to one embodiment, removal of the liner  148  at least partially removes the guard  140 , and vice versa. In the embodiment shown in  FIGS. 4-6 , the user pulls the protector  140  in a distal or downward direction. For clarity, in  FIGS. 4 and 5 , only one of the adhesive liners  148  is illustrated. In  FIG. 4 , the guard  144  still partially covers the cannula  112  and the needle  116 , and the adhesive liner  148  is partially removed from the adhesive pad  108 . In  FIG. 5 , the guard  144  no longer covers the cannula  112  and the needle  116 , and the adhesive liner  148  is not yet completely removed from the adhesive pad  108 . In  FIG. 6 , with continued distal movement of the guard  144 , the adhesive liner  148  is completely removed from the adhesive pad  108 . 
     It may be desirable to remove the liner  148  prior to completely removing the guard  140  to reduce the likelihood of a needle-stick injury. This can be accomplished by rotating the guard and pulling the guard  140  distally. The guard can then be completely removed by continuing to pull the guard  140  distally. 
     As another example, it may be desirable to completely remove the guard  140  prior to completely removing the liner  148 . This can be accomplished with, for example, an accordion-like liner with several folds, particularly if the cannula is short. With such a liner, the guard can be distally pulled completely off of the cannula while the liner remains on the adhesive. But continued pulling removes the liner because the liner and the guard are connected. Such an accordion liner is an example of a type of “lost motion” connection in which there is a time delay between the action on one of the guard and the liner and the action on the remaining one of the guard and the liner. Put another way, as an example other than the accordion liner, some movement of the guard does not immediately remove the liner. According to one embodiment, however, removal of the guard  140  and the liner  148  is substantially simultaneous. 
     According to another embodiment, removal of the guard turns up a corner of the liner, allowing the user to easily grasp the turned-up corner to manually remove the liner. 
     As another example of operation, after the user installs the medical device  100  in an insertion device (not shown) and loads (for example, the spring) the insertion device, the user then removes the connected guard  140  and liner  148 . This permits the user to load the insertion device without risking a needle-stick injury or risking degrading the adhesive prior to insertion. 
       FIGS. 7-10  are perspective front views of protectors in accordance with alternative embodiments of the present invention. For example, in  FIG. 7 , the peripheral edges of the arms  172  of the protector  168  are curved. In  FIG. 8 , the arms  180  of the protector  176  are substantially triangular, and in  FIG. 9 , the arms  188  of the protector  184  are substantially rectangular. In contrast to the protectors  168 ,  176 , and  184 , in which the arms are substantially vertically straight, the arms  196  of the protector  192  in  FIG. 10  curve along a vertical path. Such a design can provide a more contoured and comfortable fit with a user&#39;s fingers. Additionally, compared with the protector  140  of  FIG. 3 , each of the protectors  168 ,  176 ,  184 , and  192  has an increased user gripping area to aid a user in grasping the protector. 
       FIG. 11  is a perspective bottom view of a protector  200  in accordance with an embodiment of the present invention. Like the protector of  FIG. 3 , the protector  200  has a plurality of arms  204  extending from a guarding portion  208 , but the arms  204  are joined by web portions  212 . The web portions  212  can increase the stability of the arms  204 . The web portions are illustrated as being sectors of a disc, but other web portions can be employed without departing from the scope of the present invention. For example, a web portion can be a bar or bars connecting adjacent arms  204 . Such bars can be substantially straight, or can be curved. It will be appreciated that the adhesive liner  214  can be connected to the web portion, either instead of, or in addition to being connected to one or more of the arms  204 . 
     The protector  200  also has an indicator  216  indicating a preferred direction for removal of the protector. For example, the indicator  216  can indicate a rotational direction. It will be understood that, without departing from the scope of the present invention, the indicator can indicate an axial direction, or there can be multiple indicators, for example, one indicator illustrating a rotational direction and one indicator illustrating an axial direction. Further, such multiple indicators can indicate a preferred order of operations. 
       FIGS. 12-15  are bottom views of protectors in accordance with additional embodiments of the present invention. In  FIG. 12 , the protector  220  has a single, radially curved arm  224 . The slit  228  is also curved. Similarly, in  FIG. 13 , the arm  236  and the slit  240  of the protector  232  is S-shaped. As with the protector of  FIG. 10 , the curved arm  224  and the S-shaped arm  236  can provide a more contoured and comfortable fit with a user&#39;s fingers. 
     The connecting portion of the protector  244  in  FIG. 14  includes a disc  248 . Such an embodiment permits greater surface area connection between the connecting portion and the liner  252  than, for example, the arms  160  of  FIG. 3 . Similarly, in  FIG. 15 , the disc  260  of the protector  256  has cutout portions  264  that can reduce the amount of material of the guard. Such cutout portions  264  can be aligned with slits  268  of the liner  272  (as depicted in  FIG. 15 ), or can be offset from the slits  268 . According to one embodiment, however, the liner does not include a slit. 
     Although using adhesive or double-sided tape has been previously described for connecting the adhesive liner with the guard, other methods of connection can also be employed without departing from the scope of the present invention. For example, a mechanical fastener, such as a screw or pin can be used to secure the adhesive liner to the guard. Additionally, the guard can have a slit through which a portion of the liner is threaded or clamped. Further, a portion of the liner can be folded over a portion of the guard, for example, an arm. It will also be understood that the connection between the guard and the liner can be temporary. That is, subsequent to the removal of at least a portion of the protector, the guard and the liner can become disconnected. For example, if the liner is simply folded over an arm or arms of the guard, and the user rotates and/or distally pulls the guard until the liner is removed but the guard still protects a portion of the introducer needle and/or the cannula, the liner can fall away from the guard prior to the complete removal of the guard. 
     Moreover, although embodiments of the present invention have been described in conjunction with an infusion set, it will be appreciated that embodiments of the present invention can also be employed with patch pumps, IV catheters, continuous glucose monitoring devices, or other medical devices with an insertable cannula and an adhesive to secure the device to the patient&#39;s skin. 
     Embodiments of the present invention combine the steps of removing a cannula guard and peeling off an adhesive release liner into one single step. Because the liner and the guard are connected, either directly or indirectly, a user either pulls or twists and pulls the guard off the base and the liner is thereby also removed, or vice-versa. Particularly for an infusion set, the single-step removal can permit the adhesive liner to remain in place when the user places the infusion set into an insertion device and loads the insertions device (e.g., the spring), thereby avoiding catching the adhesive on the insertion device during these operations. 
     Although only a few embodiments of the present invention have been shown and described, the present invention is not limited to the described embodiments. Instead, it will be appreciated by those skilled in the art that changes may be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.