Subcutaneous infusion device and method

An infusion device including a site and a set for delivery of a substance to a patient. The site can include a cannula that is introduced into a subcutaneous layer of skin of the patient. The set can be coupled to the site by, for example, placing the set over the site and moving the set from an unlocked to a locked position. The substance can then be delivered through the set to the site, and from the site into the patient through the cannula. The set can be oriented at multiple rotational orientations with respect to the site, and can be coupled and uncoupled with the site multiple times.

TECHNICAL FIELD

The present invention relates to an infusion device for delivery of a substance to a patient.

BACKGROUND

Infusion devices are used to deliver substances such as medications into the subcutaneous layer of skin of a patient. Typically, an infusion device includes a cannula that is introduced into the skin, as well as a tube extending from the infusion device to, for example, an infusion pump to deliver the substance.

In current designs, it is typically necessary to introduce a cannula of the infusion device into the skin while maintaining the device at a given orientation so that the tubing extends in a direction towards the infusion pump. Further, once the infusion device is placed on the skin, there is typically no way to reorient the device and associated tubing, or to remove the tubing from the body without removing the cannula from the skin of the patient. In addition, the profile of infusion devices can be undesirably high, making placement and concealment of the infusion device difficult and uncomfortable to wear. Also, introduction of the infusion device into the skin can be complicated and require two hands to accomplish.

It is therefore desirable to provide new designs for infusion devices used to deliver a substance into the skin of a patient.

SUMMARY

Embodiments made in accordance with the present invention are related to infusion devices for delivery of a substance to a patient.

In one embodiment, an infusion device can include a site and a set. The site can include a cannula that is introduced into a subcutaneous layer of skin of the patient. The set can be coupled to the site by, for example, placing the set over the site and moving the set from an unlocked to a locked position. A substance can then be delivered through the set to the site and from the site into the patient through the cannula.

The set can preferably be oriented at multiple rotational orientations with respect to the site, and can preferably be coupled and uncoupled with the site multiple times.

The above summary of the present invention is not intended to describe each disclosed embodiment or every implementation of the present invention. Figures in the detailed description that follow more particularly exemplify embodiments of the invention. While certain embodiments will be illustrated and described, the invention is not limited to use in such embodiments.

DETAILED DESCRIPTION

Embodiments of the present invention relate to infusion devices for delivering a substance into the subcutaneous layer of skin of a patient.

Generally, the example infusion devices disclosed herein include a site with a cannula that is introduced into the subcutaneous layer of the skin of a patient to deliver a substance, as well as a set that can be coupled to the site to deliver the substance to the site.

Referring now toFIGS. 1-7, an example embodiment of a site100of an infusion device is depicted in accordance with the present invention. Generally, the site100can be used in conjunction with a set (described below) to deliver a substance into a patient.

The site100includes a base110, a cannula130, a diaphragm150, and an adhesive portion170. The cannula130of the site100can be introduced into the subcutaneous layer of skin of the patient using a needle (e.g., needle139), as shown inFIG. 6A. The adhesive portion170allows the base110of the site100to be coupled to the skin of the patient. The diaphragm150is in fluid communication with the cannula to deliver a substance from the diaphragm150, through the cannula130, and into the skin of the patient, as described further below.

Referring now toFIGS. 8-11, the base110is shown. The base includes a stand114with a top side111and a bottom side112, and forms a central aperture113located at a central axis C of the base110. The stand114further forms eight positional slots115on the top side111positioned radially with respect to the central axis C of the site110at regular intervals.

The base110also includes a member120coupled to the stand114, the member120being positioned about the central aperture113of the stand144and including eight surfaces124. In one preferred embodiment, the member120is non-cylindrical in shape. For example, in the embodiment shown the member120is octagonal in shape, although other shapes can also be used, as noted below. The non-cylindrical shape of member120defines different mounting orientations for a set that can be coupled to the site100.

An interior wall of the member120forms a cylindrical cavity121, and an exterior periphery of the member120forms a groove122extending about the exterior periphery. In addition, the member120forms eight apertures123extending from the interior cavity121to the groove122in the exterior of the member120.

Referring now toFIGS. 12-14, the cannula130is illustrated. The cannula130includes first and second ends132and134. The first end132of the cannula130includes a flange portion136having a tapered bottom side140, as well as a tapered portion138described further below. The cannula130also includes a central bore142extending from the first end132to the second end134to allow a substance to be introduced at the first end132and delivered out of the second end134.

The cannula130is positioned within the cavity121of the base110so that the bottom taper140of the cannula130engages tapered bottom surfaces125of the cavity121of the member120, and the second end134of the cannula130extends through the central aperture113of the stand114at an approximate right angle to the bottom side112of the stand114. SeeFIG. 6. Preferably, the bottom taper140of the cannula130is positioned adjacent to the stand114of the base110.

Preferably the cannula130is made of fluorinated ethylene propylene (FEP). Other materials can also be used, such as polytetrafluoroethylene (PTFE), or other suitable plastics.

Referring now toFIGS. 15-17, the diaphragm150is shown. Generally, the diaphragm150functions as a septum or seal that allows a needle to access an internal portion of the septum to deliver a substance provided, for example, from an infusion device or other similar device to the cannula130.

Preferably, the diaphragm150is generally cylindrical in shape and includes an open bottom end152and a closed top end154. The diaphragm150also includes a tapered portion156adjacent the bottom end152, and a central reservoir158.

As shown, for example, inFIGS. 6 and 17, the diaphragm150is positioned in the cavity121of the member120and preferably includes an outer periphery160that is sized to frictionally engage the interior cavity wall of the member120to retain the diaphragm150in the cavity121. In addition, the tapered portion156of the diaphragm150is configured to engage the tapered bottom surfaces125of the base110. The bottom end152engages the first end132of the cannula130to provide fluid communication between the reservoir158and the bore142of the cannula130.

More specifically, surfaces157adjacent to the bottom end152of diaphragm150preferably are compressed against the first end132of the cannula130to provide a seal with respect to the cannula130so a substance can be delivered from the diaphragm150, through the cannula130, and into the patient. In alternative embodiments, additional structure such as, for example, an O-ring can also be provided between the diaphragm150and cannula130to provide additional sealing.

In a preferred embodiment, the diaphragm150is made of a silicone elastomer. Other materials can also be used, such as ethylene propylene or other suitable elastomeric materials.

As previously noted, preferably the diaphragm150is retained in the cavity121of the member120of the base110through the frictional engagement of the outer periphery160of the diaphragm150with the walls of the cavity121. In alternative embodiments, a retaining member can be fitted over the open top of the member120to further retain the diaphragm150in position in the cavity121. In other embodiments, the diaphragm150can be retained in the cavity121through compression by other features of the member120, or the diaphragm150can have features that mate with features of the member120. For example, in one alternative embodiment, the diaphragm150can be formed with barbs on the outer periphery160positioned and sized to be received within apertures123formed in the member120to retain the diaphragm150in the cavity120. Other configurations are also possible.

Referring now toFIGS. 18-20, the adhesive portion170is shown. The adhesive portion includes liners172and176sandwiching a layer174. Preferably, the layer174includes an aperture178through which the cannula130of the site100extends, as described below.

The liner172can be removed and the layer174coupled to the bottom side112of the stand114of the base110using an adhesive. Examples of such adhesives include, without limitation, acrylic adhesive, synthetic rubber-based adhesive, acrylate adhesive, and silicone-based adhesive. In addition, the liner176can be removed and an adhesive be provided on a bottom side of the layer174to couple the adhesive portion170and associated site100to another adhesive portion or the skin of the patient, for example.

In a preferred embodiment, layer174of the adhesive portion170includes films with adhesives thereon, such as and without limitation, 3M™ 1577 tape. Other materials can also be used.

In an alternative embodiment, layer174can be provided with a tab (not shown, but preferably similar to tabs shown on liners172and176) or other similar structure that can assist the patient in removing the layer174and associated site100from the skin when desired. For example, the tab can extend from an outer periphery of the layer174and allow the patient to grasp the tab and thereby peel the layer174from the skin to remove the site100.

In other alternative embodiments, the adhesive portion170can be removed completely, and adhesion between the site100and skin of the patient can be provided using film and/or adhesive carried on other structures, such as a device used to insert the site100into the body, as described further below.

In other alternative embodiments, the layer174can include a foam backing or similar additional material can be added adjacent to the layer174to provide supplemental cushioning as the site100is inserted into the skin of the patient. Further, in other embodiments the layer174can be replaced or supplemented by one or more other layer of other material such as, for example, a Tegaderm™ film manufactured by 3M™ or an IV300™ film manufactured by Smith & Nephew.

Referring now toFIG. 21, an example embodiment of a set200of an infusion device is depicted in accordance with the present invention. As noted generally above and described further below, the set200can be used in conjunction with a site (e.g., site100) to deliver a substance into a patient.

The set200generally includes a first member210and a second member250. The first member210is slideable relative to the second member250into an unlocked position (see, e.g., FIGS.21and32-35) and a locked position (see, e.g.,FIGS. 36-42), described further below.

Referring now toFIGS. 22-26, the first member210is shown. The first member210includes a main body212, and a port213extending through the body212and in fluid communication with a hollow needle214. The port213is preferably coupled to a tube (e.g., tube305shown inFIG. 21) that can be attached, for example, to an infusion pump for the delivery of a substance to the set200.

The first member210also includes outer arms220and222with barbs223formed on the ends and projections230extending below the arms220. In addition, the first member210includes inner arms226and228with barbs229. As described further below, the outer arms220and222can be displaced towards one another when force is applied to surfaces221.

Referring now toFIGS. 27-31, the second member250is shown. The second member250includes a main body260, and a central octagonal aperture270. The second member250also includes opening262extending to the central aperture270, as well as openings264positioned on opposite sides of the main body260. The second member250also includes projections266formed on a bottom surface274of a base261, as well as slots268preferably extending through the base261of the main body260.

Referring now to FIGS.21and32-35, the first and second members210and250of the set200are shown in the unlocked position. The first member210is slidingly received by the second member250such that inner arms226and228are accepted into opening262of the second member250. Projections230on outer arms220and222of the first member210are received in slots268of the second member250.

As illustrated byFIG. 35, in the unlocked position barbs229of inner arms226and228of the first member210extend through openings264and engage shoulders271of the second member250such that the first and second members210and250cannot be further separated.

Referring now toFIGS. 36-42, the first and second members210and250of the set200are shown in the locked position. To move the set200from the unlocked to the locked position, the first and second members210and250are slid towards one another, and outer arms220and222of the first member210are accepted into the openings264of the second member250. Likewise, projections230on outer arms220and222slide along slots268of the second member250. Further, surfaces234of the inner arms226and228partially extend into aperture270, as described further below.

As illustrated byFIG. 42, in the locked position outer arms220and222extend through openings264and engage lips272of the second member250. In addition, inner arms226and228of the first member210extend further into the second member250. In this locked position, the engagement of the barbs223with the lips272resist allowing the first member210from being slid relative to the second member250.

In order to slide the first member210away from the second member250from the locked position back to the unlocked position, the outer arms220and222are deflected inwardly toward one another by applying pressure on surfaces221until the barbs223clear the lips272, thereby allowing the first member210to be slid with respect to the second member250back into the unlocked position as shown in FIGS.21and32-35.

Preferably, slots268formed in the second member250include a cammed surface269so that projections230extending below the arms220of the first member210are biased towards a first end267of the slots268to thereby bias the first member210into the unlocked position. SeeFIGS. 40 and 41. In alternative embodiments, other features can be provided to bias the first member210into the unlocked position. For example, detents can be provided to engage barbs229as inner arms226and228of the first member210are moved towards the locked position to bias the first member210into the unlocked position. It can be preferable to bias the set200into the unlocked position so that the set200can be easily positioned onto and removed from the site100, as described further below.

Referring now toFIGS. 43-50, as previously noted the site100and set200can be used together to form an infusion device300for delivery of a substance to a patient.

One method of use of the infusion device300is as follows. Initially, the site100is positioned on the skin of a patient with the cannula130being introduced into the subcutaneous layer of the skin. This can be accomplished, for example, using a needle (e.g., needle130shown inFIG. 6A) that is extended through the exposed closed end154of the diaphragm150and through the bore142of the cannula130and beyond the second end134. The tapered portion138of the flange portion136of the cannula130can assist in directing the needle through into the bore142of the cannula130. In this position, the needle can be used to introduce the cannula130of the site100into the skin of the patient. Further, once the cannula130is in position, the needle can be removed, leaving the cannula130in place in the subcutaneous layer of the skin. As the needle is removed, the closed end154of the diaphragm150reseals itself to retain the fluid-tight reservoir158.

In a preferred embodiment, the site100of the infusion device300is placed in position on the skin of a patient using a device made in accordance with that disclosed in U.S. patent application Ser. No. 10/705,725, entitled “Device and Method for Insertion of a Cannula of an Infusion Device,” filed on even date herewith, the entirety of which is hereby incorporated by reference. Other methods and devices for inserting the infusion device into the skin of the patient can also be used. For example, in an alternative embodiment the site100can be inserted manually using a needle. See needle139shown inFIG. 6A.

Once the site100has been positioned on the skin of a patient (with the cannula130having been introduced into the subcutaneous layer), the set200can be coupled to the site100as follows. With the set200in the unlocked position, the set200can be placed over the member120so that the central octagonal aperture270of the set200accepts the member120into the aperture270. The set200is lowered onto the site100until the bottom surface274of the set200contacts the stand114of the site100and projections266of the second member250are accepted into the positional slots115of the stand114of the base110.

In this position on the site100, the first member210of the set200can be slid from the unlocked to the locked position. As the first member210is slid to the locked position, surfaces234of the inner arms226and228(seeFIGS. 23,36, and37) are accepted by the groove112of the member120of the base100, which locks the set200to the site100so that the set200resists any upward force tending to remove the set200from the site100when the set200is in the locked position. In addition, the shape of the member120of the site100and the central aperture270of the set200, as well as projections266received in slots115, orient the set200with respect to the site100and function to resist rotation of the set200with respect to the site100when the set200is in the locked position.

In addition, as the first member210of the set200is moved from the unlocked to the locked position, the needle214is advanced through one of the eight apertures123formed in the member120and into the diaphragm150in the cavity121. In the fully locked position as shown inFIG. 50, an end215of the needle214is positioned within the reservoir158of the diaphragm150. In this position, the port213is fluidly coupled to the cavity121of the diaphragm150through the hollow needle214, and the cavity121is in turn fluidly coupled to the skin of the patient through the bore142in the cannula130. In this manner, a substance can be delivered to the port213of the set200(by, for example, a tube not shown in the figures), through the needle214, into the reservoir158, and into the subcutaneous layer of the skin of the patient by the cannula130.

If the set200is not oriented as desired with respect to the site100, or if the patient desires to remove the set200from the site100, the set200can be moved from the locked to the unlocked position by forcing the outer arms220and222together and sliding the first member210away from the second member250to the unlocked position. This action removes the surfaces234from the groove122, as well as the needle214from the reservoir158. The diaphragm150reseals upon removal of the needle214. The set200can then be removed from the site100, leaving the site100in place on the skin of the patient. The set200can be replaced at another orientation or at a later time.

In the illustrated embodiment of the infusion device300, the set200can be oriented in eight different positions with respect to the site100. In alternative embodiments, the site100and set200can be configured to include fewer or more positions as desired. For example, in an alternative embodiment the member120of the site100and the aperture270of the set200can be formed in the shape of a square if four orientational positions are desired.

Referring now toFIGS. 51-53, another example infusion device400is shown in accordance with the present invention. The device400is similar to the example device300described above, except for the details noted below.

The infusion device400includes a site405with a central portion407. The central portion407includes a pierceable outer shell430made of a material such as a plastic, and a softer inner diaphragm432surrounding the outer shell430. An inner reservoir434of the central portion407is fluidly coupled to a cannula440. SeeFIG. 53.

The infusion device400also includes a set with a first member410and a second member420. The first member410includes a needle411, and first and second arms412and414with barbs415on ends. The second member420includes shoulders422and424. The first and second members410and420each form openings461and462, respectively, that are sized to each receive a portion of the central portion407of the site405.

The infusion device400can be used as follows. First, the site405is positioned on the skin of a patient so that the cannula440is introduced into the subcutaneous layer. Next, the first member410and second member420of the site are placed onto the site405so that openings461and462are positioned about the central portion407, and the first and second members410and420are slid towards one another from the unlocked to the locked position. As the set is moved to the locked position, the needle411is introduced into the central portion407of the site405, moving through the outer shell430and into the reservoir434to become fluidly coupled to the cannula440. In addition, the arms412and414are accepted into the second member420until barbs415engage the shoulders422and424in the locked position, as shown inFIG. 52.

To move the set from the locked position back into the unlocked position, the barbs415are pressed inwardly toward one another until they clear the shoulders422and424, and then the first member410is slid away from the second member420, thereby removing the needle411from the central portion407of the site405.

As preferably there is no specific structure provided with infusion device400for rotationally orienting the set with the site405, the set can be oriented at an infinite number of rotational positions with respect to the site405as desired. Further, since the central portion407of the site and the openings461and462of the set are preferably circular in shape, the first and second members410and420of the site can be rotated relative to the site405without requiring that the set be completely removed from the site405.

Infusion devices made in accordance with the principles described herein can be advantageous for various reasons. For example, the set can be coupled in various selectable rotational orientations with respect to the site. In some embodiments, a plurality of orientations can be provided. This allows a patient to rotationally orient the set (and associated tube coupled to the set) as desired so that the tube can extend, for example, towards an infusion pump regardless of where the site is placed on the body of the patient.

In addition, the set and associated tube can be removed from the site multiple times while leaving the site on the skin. This can be desirable if the patient wants to reorient the set with respect to the site, or if the patient wants to remove the set from the site for a period of time, such as if the patient wishes to shower and then replace the set onto the site.

The engagement of the set with the site and sliding action of the set from the unlocked to locked position can also be advantageous in that a patient can preferably accomplish orientation and coupling of the set to the site using a single hand. This can be preferable, for example, if the site has been placed on a portion of the body of the patient that is not easily reached using two hands, or cannot easily be seen by the patient (e.g., if the site is placed on the back of the patient).

Further, the configuration of the set functions to protect the patient from inadvertent contact with the hollow needle (e.g., needles214and411) used to pierce the diaphragm and deliver the substance to the site. For example, the outer arms220and222and the inner arms226and228of the first member210of the set200generally surround the needle214and function to reduce the chance that the patient will inadvertently contact the needle.

Also, the configuration of the diaphragm in the site can be preferable in that a single diaphragm can function to both allow introduction of the cannula of the site into the body using one needle, as well as coupling of the set with the site using a second needle. In addition, the diaphragm can preferably be held within the site through frictional engagement between the diaphragm and the site without requiring additional structure to retain the diaphragm in the site.

Although examples of infusion devices have been described herein, various modifications can be made to the devices. For example, as noted above the member120of the site100and the aperture270of the set200can be formed in a variety of shapes to allow the set200to be oriented in multiple positions with respect to the site100. In addition, a retaining member can be fitted over the open top of the member120to further retain the diaphragm150in position in the cavity121.

In another alternative embodiment, the second member250of the site200can be constructed to include a cover portion extending from the main body260so that when the set200is moved to the locked position the cover extends over the closed end154of the diaphragm150to reduce exposure of the set and site to outside contaminants.