MEDICATION INFUSION SET
An infusion set is provided for use in delivering fluid through a cannula, which is housed on a cannula housing, to a selected subcutaneous infusion site on a patient. The fluid is generally a medication, e.g., insulin. The cannula is in fluid communication with a fluid passageway surrounded by a projection on the cannula housing that includes one or more rail-like extensions acting as guides. A connector connects the cannula housing to a fluid delivery system, e.g., an infusion pump. The connector includes a needle, one or more guide arms that slide over the rail-like extensions to guide the needle into the self-sealing septum, and one or more locking arms, with barbs at the end, to connect with corresponding recesses in the cannula housing. An introducer having one or more similar guide arms and locking arms, and a longer needle, may be used to insert the cannula into the patient.
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This application is a continuation of U.S. patent application Ser. No. 13/296,110, filed Nov. 14, 2011, which is a continuation of U.S. patent application Ser. No. 11/975,315, filed Oct. 18, 2007, now U.S. Pat. No. 8,162,876, which is a continuation of U.S. patent application Ser. No. 11/003,225, filed Dec. 3, 2004, now U.S. Pat. No. 7,303,543, all of which are incorporated herein by reference in their entirety.
BACKGROUND OF THE INVENTION1. Field of the Invention
This invention relates generally to an infusion set for subcutaneous delivery of a selected medication or other fluid to a patient. More particularly, this invention relates to an improved infusion set having a cannula housing and a connector for connecting the cannula housing to a delivery device, with the cannula of the cannula housing being inserted into the patient by a corresponding introducer.
2. Description of Related Art
Infusion sets are typically used for delivering a selected medication or other fluid to a patient. Infusion sets may include a cannula, which may be relatively soft and flexible. The cannula provides a transcutaneous passageway to administer a medication or other fluid to a subcutaneous site on a patient. The cannula generally attached to a cannula housing, which may be placed on the skin of the patient when the cannula is inserted. A connector attaches to the cannula housing to connect the cannula to the fluid delivery system. The fluid delivery system is generally placed in fluid communication with the connector by way of a length of infusion tubing. Examples of fluid delivery systems are shown in U.S. Pat. Nos. 4,562,751, 4,685,903, 5,080,653, 5,097,122, which are herein incorporated by reference.
Infusion sets of the type described above are generally used to deliver medication, such as insulin, to a patient over an extended period of time. The infusion sets usually are adapted to rest on the skin of the patient. The cannula housing may remain on the patient's skin for several days, and the patient may disconnect the connector when performing certain activities, like showering. Because a patient changes infusion sets fairly frequently, it is beneficial to have an infusion set that is easy to insert, easy to connect properly, and easy to remove and dispose of.
An infusion set of the above type is described in U.S. Pat. No. 5,522,803. The infusion set comprises a cannula housing with a cannula and a needle holder to be connected to the cannula housing. The cannula housing includes two guide openings and two locking openings with shoulders for engaging barbs on locking pins of the needle holder. The needle holder includes guide pins that co-operate with the guide openings on the cannula housing. The needle on the needle holder is guided by the guide pins into the cannula housing so that the needle penetrates a membrane at the inlet of a fluid passageway of the cannula housing. The fluid passageway is in fluid communication with the cannula. Thus, when the needle penetrates the membrane, the fluid may flow through the connector into the cannula housing and then into the patient. The guide pins must be guided carefully into the guide openings, as the guide openings surround the pins on all four sides when the cannula housing and needle holder are guided together.
Another infusion set of the above type is described in U.S. Pat. No. 6,302,866. The infusion set comprises a cannula housing with a cylindrical extension and a needle holder with a guide sleeve that closely slides over the cylindrical extension. The connection must be done carefully, because the cylindrical extension fits closely into the guide sleeve. The guide sleeve surrounds a connecting needle that is guided into the passageway of the cylindrical extension. The passageway in the cylindrical extension is in fluid communication with the cannula and has a septum at its inlet that is pierced by the connecting needle. Once the septum is pierced, fluid can flow from an infusion device through the needle holder into the cannula housing and then into the patient.
BRIEF SUMMARY OF THE INVENTIONIn accordance with the invention, an infusion set is provided for use in delivering fluid through a cannula to a selected subcutaneous infusion site on a patient. The fluid is generally a medication, for example, insulin. The cannula is a soft and flexible cannula and is supported by a cannula housing. The cannula housing also includes a fluid passageway in fluid communication with the cannula. At one end of the fluid passageway is a self-sealing septum. The fluid passageway is surrounded by a projection on the cannula housing that includes one or more rail-like extensions acting as connection guides. The rail-like extensions may be substantially triangular or otherwise suitably shaped to act as guides. The cannula housing also includes a base that rests upon a patient's skin when the cannula is inserted into the skin.
The infusion set also includes a connector that connects the cannula housing to fluid tubing that allows fluid to flow from a fluid source, which may be a fluid delivery system, such as an infusion pump, through the connector to the cannula housing and through the cannula into the patient. The connector includes a connecting needle that is mounted thereon to pierce the self-sealing septum on the cannula housing to allow flow of fluid through the needle into the fluid passageway. The connecting needle is in fluid communication with the fluid tubing. The connector also includes one or more guide arms that slide over the rail-like extensions to guide the needle into the self-sealing septum. The connector includes one or more locking arms, with barbs at the end, to connect with one or more recesses that are provided in the cannula housing. Once the barbs are pushed into the recesses, the connector is essentially locked in place with respect to the cannula housing. The connector is preferably reversible so that it may be connected to the cannula housing regardless of which side is up.
The cannula housing is inserted into the skin using an introducer. The introducer has the same guide arms and locking arms as the connector. It includes an introducing needle that passes through the self-sealing septum and fluid passageway of the cannula housing and into the cannula. When connected to the cannula housing, the tip of the introducing needle is outside the cannula.
A method of delivery of a fluid is provided comprising positioning a cannula housing according to the invention at an infusion site on a patient and engaging the cannula housing with a connector according to the invention. The positioning of the cannula housing may include using an introducer according to the invention to pierce the skin of the patient, and removing the introducer from the cannula housing once the cannula housing is positioned on the infusion site.
A detailed description of embodiments of the invention will be made with reference to the accompanying drawings, wherein like numerals designate corresponding parts in the figures.
In the following description, reference is made to the accompanying drawings which form a part hereof and which illustrate several embodiments of the present invention. It is understood that other embodiments may be utilized and structural and operational changes may be made without departing from the scope of the present invention.
As shown in
The projection 240 is generally at least partially attached along its length to the base 220. However, the projection 240 may be entirely separate from the base 220 along its length, allowing a space between the projection 240 and the base 220. The end of the projection 240 opposite the end with the septum 295 would still be attached to remainder of the cannula housing 100, such that the cannula housing 100 is still only one integral piece. The base 220 may also have a groove 260 cut into it to allow for a higher projection without the need for the entire cannula housing 100 to be taller. The projection 240 may have a relatively flat top, which can also reduce the height of the cannula housing 100 and of the infusion set and can reduce the overall volume of the infusion set. When the infusion set is thinner, it can have a lower profile and be less noticeable.
The two sides of the projection 240 on the cannula housing 100 are rail-like extensions or guide rails 242 and 244. These guide rails 242 and 244 may be substantially triangular, as shown, but they may be shaped in any other configuration that allows for guiding of the connector 120 onto the cannula housing 100. For example, they could be rectangular or peg-shaped. At the side of the cannula housing 100 near the cannula 200, there are two recesses 270 and 272 formed to receive barbs that are on locking arms of the connector. These guide rails are visible to the user, making the infusion set easier to connect. Additionally, the base of the cannula housing assists in guiding the needle, acting as a bottom boundary for a connector. The cannula is preferably angled so that the cannula is inserted into the skin at an angle. The fluid passageway and connector fluid passageway may each be similarly angled. If both are angled to match the cannula, the passage of fluid will be one straight line from the point at which the fluid enters the connector until the end of the cannula, where the fluid enters the patient's body.
As shown in
On either side of the needle 320 on the connector 120 are guide arms 350 and 352. The guide arms 350 and 352 extend alongside and past the needle 320. Because the guide arms 350 and 352 extend past the needle 320, it is difficult for the user to be injured by, or to injure, the needle 320 when the connector 120 is separated from the cannula housing 100. The guide arms 350 and 352 have indentations 351 and 353 that match the guide rails 242 and 244 of the projection 240 of the cannula housing 100. For example, if the guide rails 242 and 244 are triangular in shape, the guide arms 350 and 352 will have triangular indentations. When the user connects the connector 120 to the cannula housing 100, the guide arms 350 and 352 slide along the projection 240, guiding the needle 320 into the fluid passageway of the cannula housing 100.
The connector is preferably symmetrical, so that it is reversible and may be placed into the connector with either of its top or bottom facing upward. If the connector is symmetrical, the patient does not have to worry about which way to place the connector. This will allow for quicker and easier connection.
The cannula housing may be adhered to the patient's skin by an adhesive. The adhesive may be on a patch that is attached to the base of the cannula housing. In one embodiment, as shown in
To insert the cannula into the patient, an introducer may be used. As shown in
The cannula housing 100 can be packaged connected to the introducer. To protect the patient from injury from the needle, a needle guard may cover the introducer needle, which extends beyond the cannula. The needle guard may be a small plastic tube that covers the needle and some or all of the cannula. If a small plastic tube is used as a needle guard, it may be colored so that it is easily visible. Thus, the patient easily would be able to see if the needle guard is in place. The small plastic tube may have only holes at each end of the tube. Alternatively, it may be slit down the side for ease of removal and replacement. A slit guard may reduce damage to the cannula 200 caused by attempting to slide the small plastic tube onto the needle and cannula. A larger needle cover may also be used. The larger needle cover may connect or snap to the cannula housing. It may also act as a cover for the introducer after insertion of the cannula, when the introducer is removed from the cannula housing.
The cannula housing may be made out of a plastic, such as an acrylic or polypropylene or polycarbonate. A polycarbonate cannula housing may be transparent, so that the patient can see whether any bubbles are present in the fluid passageway. The connector may also be made out of a plastic, such as an acrylic or polypropylene or polycarbonate. As in the cannula housing, a polycarbonate connector may be transparent, so that the patient can see whether any bubbles are present in the connector fluid passageway. The plastics used for the cannula housing and the connector should be compatible with the medication or fluid selected for delivery through these parts and should pass the required biological tests for skin contact.
The patch or infusion set itself may be time-sensitive, to indicate to the patient when it is time to remove the infusion set. A time-sensitive indicator may be chemical, mechanical, or electrical. The patch itself, a portion of the patch, the infusion set, or a portion of the infusion set may contain an ink that changes color or appearance with passage of time. An infusion set is typically used for a minimum of 3 days, but may be adapted to be used for any predetermined period of time. Similarly, the time-sensitive indicator may be designed to be used for any predetermined period of time. Alternatively, a different colored patch may be used for a different day of the week, meaning the first and/or last day for the infusion set, so that the user will easily know when to change the infusion set. For example, if the color red means the first day for the set is Monday and the last day is set for Wednesday, the user will know to insert the infusion set on Monday and to remove it on Wednesday. Graphics and other designs may also be printed on the patches.
To aid in insertion of the cannula, an injector tool may be used. Injector tools may be of the type described in PCT Publication No. WO 02/100457 A2, entitled “Insertion Device for an Insertion Set and Method of Using Same,” published Dec. 19, 2002, which is herein incorporated by reference. Injector tools are useful for patients who are reluctant or hesitant to pierce their own skin with a medical needle. The injector tool is designed to place the needle through the skin at a selected insertion angle and with a controlled force and speed of insertion to ensure proper placement with minimal discomfort.
Without being limited, several other embodiments of infusion sets comprising cannula housings and connectors, and the corresponding introducers, are described below. Because the structure of the portion of the introducer that mates with the cannula housing is the same as the portion of the connector that mates with the cannula housing, each embodiment is described with respect to the introducer and cannula housing or with respect to the connector and cannula housing. It is intended that the connector and/or introducer not described has the same mating structure as the element that is described.
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While the description above refers to particular embodiments of the present invention, it will be understood that many modifications may be made without departing from the spirit thereof. The accompanying claims are intended to cover such modifications as would fall within the true scope and spirit of the present invention.
The presently disclosed embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims, rather than the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.
Claims
1. A connector device to deliver fluid from a fluid delivery device to a body of a user, the connector device comprising:
- separate first and second guide arms having no physical connection therebetween, each of the separate first and second guide arms having opposing inner and outer longitudinal sides, wherein, for each guide arm, the outer longitudinal side is flat along substantially the entire length thereof and the inner longitudinal side has an arcuate profile along substantially the entire length thereof, said inner side of the first guide arm facing the inner side of the second guide arm; and
- a longitudinally-extending connecting needle that is parallel to said guide arms and is disposed laterally spaced apart from, and in-between, said first and second guide arms, wherein the needle has a distal tip and the guide arms have respective distal ends, and the distal ends of the first and second guide arms extend beyond the needle's distal tip.
2. The device of claim 1, wherein the connector device is symmetrical about its longitudinal axis such that it is reversible.
3. The device of claim 1, wherein the inner longitudinal side of each of said first and second separate guide arms is concave.
4. The device of claim 1, wherein the connector device further includes a plurality of locking arms, each said arm having a barb associated therewith.
5. The device of claim 1, wherein the fluid delivery device is an infusion pump.
6. The device of claim 1, wherein the connector is made of material selected from the group consisting of polycarbonate and polypropylene.
7. The device of claim 1, wherein the needle is stationary at all times with respect to the first and second guide arms.
8. The device of claim 1, wherein the device is configured to be detachably connected to a cannula housing having a cannula for delivering said fluid to the user's body.
9. The device of claim 1, wherein the fluid is insulin.
10. A connector device to deliver fluid from a fluid delivery device to a body of a user, the connector device comprising:
- a first guide arm having opposing inner and outer longitudinal sides, wherein the outer longitudinal side is flat along substantially the entire length thereof and the inner longitudinal side has a concave profile along substantially the entire length thereof;
- a second guide arm separate from said first guide arm, said second guide arm having opposing inner and outer longitudinal sides, wherein the outer longitudinal side is flat along substantially the entire length thereof and the inner longitudinal side has a concave profile along substantially the entire length thereof, wherein the inner side of the first guide arm faces the inner side of the second guide arm;
- a longitudinally-extending connecting needle that is parallel to said guide arms and is disposed laterally spaced apart from, and in-between, said first and second guide arms; and
- a locking arm having a barb.
11. The device of claim 10, wherein the needle has a distal tip and the guide arms have respective distal ends, and the distal ends of the first and second guide arms extend beyond the needle's distal tip
12. The device of claim 10, wherein the connector device is symmetrical about its longitudinal axis such that it is reversible.
13. The device of claim 10, wherein said locking arm includes a grip.
14. The device of claim 10, further including a plurality of locking arms, each said locking arm having a barb associated therewith.
15. The device of claim 10, wherein the connector device is made of material selected from the group consisting of polycarbonate and polypropylene.
16. The device of claim 10, wherein the needle is stationary at all times with respect to the first and second guide arms.
17. The device of claim 10, wherein the fluid is insulin.
Type: Application
Filed: Mar 13, 2014
Publication Date: Jul 10, 2014
Applicant: MEDTRONIC MINIMED, INC. (Northridge, CA)
Inventors: Susie E. Maule (Torrance, CA), Sheldon B. Moberg (Thousand Oaks, CA), Arin N. Holecek (Houston, TX), Christopher G. Griffin (Cameron Park, CA), Julian D. Kavazov (Arcadia, CA), Paul H. Kovelman (Simi Valley, CA)
Application Number: 14/210,066
International Classification: A61M 5/158 (20060101);