US 20060129123 A1
A low-profile inserter for an angled infusion set comprises an inserter housing having a bottom wall, a retainer slidably connected to the inserter housing for movement between retracted and extended positions in a direction substantially parallel with the bottom wall, and a base member connected to the inserter housing. The retainer is adapted to releasably receive a cannula assembly, including a cannula connected to a cannula housing. The base member has a lower surface that is adapted to contact a skin outer surface. The lower surface and bottom wall together form an acute angle. With this arrangement, the cannula can be inserted subcutaneously at the acute angle with respect to the skin outer surface.
1. An inserter for a low-profile angled infusion set, the low-profile inserter comprising:
an inserter housing having a bottom wall, and a distal end defining an opening therein;
a retainer slideably mounted in the inserter housing for movement between retracted and extended positions in a direction substantially parallel with the bottom wall, the retainer being adapted to releasably receive the infusion set, including a cannula and an insertion needle, the cannula and insertion needle defining an insertion axis;
a tension spring for biasing said retainer toward said extended position, said tension spring being movable between an expanded position when said retainer is in said retracted position, and a contracted position when said retainer is in said extended position;
a release lever releasably holding the retainer in the retracted position;
a first release button for releasing said tension spring from said expanded position, said first release button movable in a direction substantially normal to said insertion axis; and
a base member connected to the inserter housing, the base member having a lower surface that is adapted to contact a user's skin surface, the lower surface and the bottom wall forming an acute angle, wherein the cannula and the insertion needle are guided to be inserted subcutaneously along the insertion axis at said acute angle with respect to the skin surface.
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8. An inserter for an infusion set, the inserter comprising:
an inserter housing defining an opening in a distal end thereof;
a retainer slideably connected to the inserter housing for movement between retracted and extended positions, the retainer being adapted to releasably receive the infusion set including a cannula and an insertion needle, the cannula and the insertion needle defining an insertion axis;
a biasing member connected between the retainer and the inserter housing for biasing the retainer toward the extended position, said biasing member being expanded when said retainer is in said retracted position, and contracted when said retainer is in said extended position;
a first release button for releasing said biasing member from being expanded, movable in a direction substantially normal to said insertion axis; and
a base attached to a lower surface of said inserter housing defining an acute angle with respect to said inserter housing, for guiding the insertion needle and the cannula to be inserted subcutaneously in skin of a user, along the insertion axis and at the acute angle with respect to the skin.
9. An inserter according to
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11. A method for inserting an insertion needle and a cannula into skin of a user, comprising the steps of:
providing an inserter housing having a bottom wall, a distal end defining an opening therein, and a base member attached to the bottom wall proximate the distal end, said base member including a lower surface adapted to contact the skin and defining an acute angle with said bottom wall;
slideably mounting a retainer within said inserter housing, movable between a retracted position and an extended position, said extended position being substantially parallel with said bottom wall of said inserter housing;
mounting the cannula and the insertion needle in said retainer to define an insertion axis;
providing a tension spring for biasing said retainer toward said extended position, movable between an expanded position and a contracted position;
releasing said tension spring by pressing a release button proximate said distal end of said inserter housing, in a direction substantially normal to the insertion axis, thereby releasing said spring to move from said expanded position to said contracted position and move said retainer to said extended position, whereby said insertion needle and said cannula are guided to be inserted subcutaneously in the skin at said acute angle with respect to the skin.
This application is a continuation of U.S. application Ser. No. 10/024,894, filed Dec. 18, 2001, which claims the benefit of U.S. application Ser. No. 60/256,573, filed Dec. 19, 2000.
This invention relates to medical devices, and more particularly to an automatic inserter for installing an angled or low-profile infusion set in the skin of a person to subcutaneously administer medication or other substances beneficial to health.
Frequent or continuous subcutaneous injection of medication such as insulin is often accomplished through the use of an infusion set or injection port which may remain in place for several days. In the case of frequent injections, the infusion set reduces the need to constantly puncture the skin, thereby minimizing the risk of infection and the formation of scar tissue. For continuous subcutaneous delivery of medication through portable insulin pumps or the like, an infusion set is often used to provide a method of temporarily detaching the pump and fluid line for activities such as dressing or bathing. It is also desirable in this instance to detach the fluid line from the pump as close to the injection site as possible, thereby leaving a relatively small component attached to the body which minimizes any interference during dressing, bathing or other activities.
Angled infusion sets, such as disclosed in my copending U.S. patent application Ser. No. 09/625,245 filed on Jul. 25, 2000, now U.S. Pat. No. 6,572,586, the disclosure of which is herein incorporated by reference, are especially advantageous due to their low profile during use. See also U.S. Pat. No. 5,522,803 issued to Tiessen-Simoney on Jun. 4, 1996. Such devices include a manual inserter with a handle and an introducer needle that attach to a cannula housing. A self-adhesive pad on the bottom surface of the cannula housing secures the housing to the skin of a person. To insert the infusion set, the user grasps the handle with one hand while pinching a fold of skin between the thumb and forefinger of the other hand. The introducer needle together with the outer end of the cannula are then pushed by the user into the fold of skin. The introducer needle is removed from the cannula housing leaving the cannula inserted in the subcutaneous layer. The housing is then adhesively secured to the skin. A tubing connector from an insulin pump can then be connected to the cannula housing to deliver insulin or other substances to the subcutaneous layer.
While this process is relatively straightforward for more experienced persons, it does require manual dexterity. In addition, the cannula may become kinked during an improper installation and impede the flow of insulin, or may be positioned in an improper skin layer. Surrounding tissue may also be damaged during attempts to correctly position the cannula, causing added pain and trauma to a user. Many users prefer to avoid the trauma associated with self-inserting the introducer needle and cannula into their bodies.
Accordingly, it would be desirous to provide an automatic inserter for angled or low-profile infusion sets, thereby assuring the correct placement of the cannula in the subcutaneous layer at the correct angle while minimizing the trauma associated with cannula installation.
According to one aspect of the invention, a low-profile inserter for an angled infusion set comprises an inserter housing having a bottom wall, a retainer slidably connected to the inserter housing for movement between retracted and extended positions in a direction substantially parallel with the bottom wall, and a base member connected to the inserter housing. The retainer is adapted to releasably receive a cannula assembly, including a cannula connected to a cannula housing. The base member has a lower surface that is adapted to contact an outer skin surface. The lower surface and bottom wall together form an acute angle. With this arrangement, the cannula can be inserted subcutaneously at the acute angle with respect to the outer skin surface.
According to a further aspect of the invention, an inserter for an infusion set comprises an inserter housing, and a retainer slidably connected to the inserter housing for movement between retracted and extended positions. The retainer is adapted to releasably receive the cannula assembly. A biasing member is connected between the retainer and the inserter housing for biasing the retainer toward the extended position. A first release lever is pivotally mounted to the inserter housing. The first release lever includes a first end portion that is exposed through the housing for manipulation by an operator and a second end portion for engagement with the retainer to thereby hold the retainer in the retracted position. In this manner, pivotal movement of the first release lever in a first rotational direction causes disengagement of the second end portion and the retainer to thereby release the retainer.
The foregoing summary, as well as the following detailed description of preferred embodiments of the invention, will be better understood when read in conjunction with the appended drawings. For the purpose of illustrating the invention, there is shown in the drawings embodiments which are presently preferred. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. In the drawings:
It is noted that the drawings are intended to represent only typical embodiments of the invention and therefore should not be construed as limiting the scope thereof. The invention will now be described in greater detail with reference to the drawings, wherein like parts throughout the drawing figures are represented by like numerals.
Referring now to the drawings, and to
With reference now to
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The release button 66 is normally biased upwardly by means of a tension spring 82 connected between a forwardly extending hook 84 of the retainer 30 and a rearwardly extending hook 86 of the release lever 60. In this position, the cannula housing 28 is locked to the retainer 30 and is slidable therewith along the housing 12 between the extended and retracted positions. Since the release lever 60 is pivotally connected to the retainer 30, it is also slidable with the retainer to maintain the cannula housing in a locked position until the housing is released by depressing the release button 66. When the retainer 30 is retracted, the release button 66 is located within the housing 12 and therefore cannot be accessed until the retainer is extended to expose the release button. In this manner, the cannula housing 28 cannot be inadvertently released during handling or positioning of the inserter assembly 10, to thereby reduce the possibility of cannula contamination and/or injury. Depression of the release button 66 when the retainer 30 is extended causes the release lever 60 to rotate (clockwise as viewed in
As shown in
A retainer release lever 98 (
In order to retract the retainer 30, including the attached cannula housing 12, to a cocked position, the levers 90 (
Once in the retracted position, the inserter assembly can be placed on the skin of a patient with the lower surface 20 of the base 18 positioned against a user's or patient's outer skin 22. The release button 102 can be depressed to rotate the catch 106 out of the recess 108, which causes the retainer 30 to slide forwardly to the extended position under force from the springs 92 at a relatively rapid rate. Forward movement of the retainer in this manner causes the needle 27 and cannula 26 to pierce the skin at the proper angle and enter into the subcutaneous layer at the proper distance. The cannula housing 28 can then be released from the inserter assembly 10 by depressing the release button 66, as previously described. The mounting pad 80 can then be secured to the skin and the needle 27 removed in a well-known manner, thus leaving the cannula 26 in place.
A safety button 120 is mounted in the upper housing portion 14 between the guide flanges 32 for limited forward and rearward sliding movement. The safety button 120 includes an upper portion 122 that extends through a rear opening 124 in the top wall 105 for grasping by a user. A pair of resilient arms 126 (only one shown in
With reference now to
With reference now to
The bottom wall 25 is formed in a depression 162 of the lower housing portion 16 and is defined by a pair of inner side walls 164 (only one shown in
Operation of the inserter assembly 150 is similar to the operation of the inserter assembly 10, with the exception that a user sets the retainer in a retracted position by pushing the head portion 156 of the cocking lever 154 rearwardly until the catch 106 is located in the recess 108 of the retainer to thereby hold the retainer in the retracted position under bias force from the springs 92. The head portion 156 is preferably entirely located within the depression 162 of the lower housing portion 16 to prevent interference between the head portion and other objects, such as the skin or clothing of a user, and thus possible injury or misplacement of the cannula assembly in the skin during release of the retainer 30.
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A generally vertically extending channel 190 is formed in a forward end of the housing 172. Preferably, the channel is wide enough to receive the cannula housing 28 and the mounting pad 80. A generally horizontally extending slot 192 is formed between the upper housing portion 174 and lower housing portion 176 and intersects with the channel 190. The slot 192 is dimensioned to receive the cannula housing 28, the mounting pad 80, and the release button 66 so that the cannula housing and mounting pad can be releasably connected to the retainer and moved into and out of the housing 172 without obstruction.
It will be understood that the terms relating to orientation and/or position, such as upper, lower, forward, rearward, downward, bottom, and side, including their respective derivatives, as may be used throughout the specification, refer to relative rather than absolute orientations and/or positions.
While the invention has been taught with specific reference to the above-described embodiments, those skilled in the art will recognize that changes can be made in form and detail without departing from the spirit and the scope of the invention. For example, although the present invention has been described for use with a low profile or angled infusion set, it will be understood that the invention may be used to insert straight infusion sets or other types of needles and/or cannulas. Thus, the described embodiments are to be considered in all respects only as illustrative and not restrictive. The scope of the invention is, therefore, indicated by the appended claims rather than by the foregoing description. All changes that come within the meaning and range of equivalency of the claims are to be embraced within their scope.