On-body medical devices often include adhesive layers for securing the on-body medical devices to the user. The adhesive layers contain adhesives that adhere to the skin of the users to hold the on-body medical devices in place on the users. To secure such an on-body medical device to the skin, the user presses the adhesive layer against the skin until the adhesive layer securely adheres to the skin. Most on-body medical devices have fairly short lifespans of use, such as for a few hours or a few days. When the end of the lifespan of use is reached, the on-body medical device is removed by peeling the adhesive layer off of the skin of the user.
Choosing the best adhesive for an adhesive layer of an on-body medical device can be difficult. The adhesive must be strong enough to keep the on-body medical device secured to the user for the entire lifespan of use. Otherwise, the adhesive may fail and the on-body medical device may become detached from the user. However, the adhesive also must not be too strong. If the adhesive is too strong, it may be painful for the user to peel off the adhesive layer at the end of the lifespan of use. A too strong adhesive also may cause skin damage to the user when the adhesive layer is peeled off. Most conventional on-body medical devices tend to have strong adhesives to prevent detachment of the on-body medical devices from the skins of the users.
In accordance with an inventive facet, an on-body medical device includes a skin-facing surface configured for facing the skin of a user. The device also includes an adhesive layer secured to the skin-facing surface for securing the on-body medical device to the skin of the user. The adhesive layer includes a stronger adhesive positioned around an outer perimeter of the adhesive layer and a weaker adhesive positioned inside the outer perimeter of the adhesive layer. The stronger adhesive is at least 20% stronger than the weaker adhesive.
The on-body medical device may additionally include a needle and/or cannula insertion assembly for inserting a needle and/or cannula through the skin of the user to deliver a medicament to the user. The device may also include an opening in the skin-facing surface, and an opening in the adhesive layer that is aligned with the opening in the skin facing surface to create a path for the needle and/or cannula to pass for enabling the needle and/or the cannula to be inserted through the skin of the user. The stronger adhesive also may surround a perimeter of the opening in the adhesive layer. The device may include an intermediate strength adhesive that surrounds the opening in the adhesive layer. The intermediate strength adhesive may be weaker than the stronger adhesive but stronger than the weaker adhesive. The weaker adhesive may be a 1 day wear time adhesive or a 2 day wear time adhesive. The stronger adhesive may be a 3 day wear time adhesive or a 4 day wear time adhesive. In this case, “wear time” may refer to an average wear time for a typical user under typical conditions. Alternatively, the stronger adhesive may be 10% to 100% stronger than the weaker adhesive, or more particularly, 10% to 50%; or in an exemplary embodiment, 20% stronger. The on-body medical device may be a medicament delivery device. The medicament delivery device may be an insulin pump. The skin-facing surface may be a surface on the housing of the on-body medical device. The device may include a hole in the adhesive layer, and the stronger adhesive may be positioned on the adhesive layer around a perimeter of the hole.
In accordance with another inventive facet, an on-body medical device includes a housing having a skin-facing surface configured for facing the skin of a user. The device also includes an adhesive layer secured to the skin-facing surface of the housing for securing the on-body medical device to the skin of the user. The adhesive layer includes what may be termed “islands” on the adhesive layer where no adhesive is present or where a weaker strength adhesive (relative to the other adhesive) is present, and may include a stronger strength adhesive applied around a perimeter of the adhesive layer, and may also include a stronger strength adhesive around a region interior to the perimeter so as to surround the islands. Accordingly, the islands of no adhesive or weaker strength may be defined by their complete perimeter being surrounded by a stronger adhesive. The stronger strength adhesive may be 10% to 100% stronger than the weaker adhesive, or more particularly, 10% to 50%; or in an exemplary embodiment, at least 20% stronger than the weaker strength adhesive.
The islands may be periodically spaced apart. The islands may be arranged in a grid. The islands may have the weaker adhesive present, and the weaker adhesive may be a 1 day wear time or a 2 day wear time adhesive. The stronger adhesive may be a 3 day wear time or a 4 day wear time adhesive. In some embodiments, the stronger adhesive may be a 3 to 28 days wear time adhesive, more specifically a 3 to 10 days wear time adhesive and in particular a 3 to 5 days wear time adhesive. A 1 day wear time adhesive may be defined as an adhesive that looses more than 50% of its peel strength within 1 day of being in contact with the user's skin. A 3 day wear time adhesive may be defined as an adhesive that loses more than 50% of its peel strength within 3 day of being in contact with the user's skin, but less than 50% within 2 days of being in contact with the user's skin. In some embodiments, the stronger adhesive is an acrylate based adhesive. In some embodiments, the weaker adhesive is a silicone based adhesive.
In accordance with an additional inventive facet, an on-body medical device includes a skin-facing surface configured for facing the skin of a user and an adhesive layer secured to the skin-facing surface for securing the on-body medical device to the skin of the user. In reverse of the earlier embodiment, the adhesive layer may include “islands” on the adhesive layer where a stronger strength adhesive is present and a weaker strength adhesive applied around a perimeter of the adhesive layer and also applied around a region interior to the perimeter so as to surround the islands with the weaker strength adhesive. Accordingly, the islands of stronger adhesive may be defined by their complete perimeter being surrounded by a weaker adhesive. The stronger strength adhesive may be 10% to 100% stronger than the weaker adhesive, or more particularly, 10% to 50%; or in an exemplary embodiment, at least 20% stronger than the weaker strength adhesive.
The islands may be periodically spaced apart. The islands may be arranged in a grid. The device may further include a needle and/or cannula insertion assembly for inserting a needle and/or cannula through the skin of the user to deliver a medicament to the user, an opening in the skin-facing surface, and a corresponding opening in the adhesive layer for enabling the needle and/or the cannula to be inserted through the skin of the user.
In another exemplary embodiment, the adhesive may form a gradient of strength from an outer perimeter (where the adhesive may be stronger) toward the center (where the adhesive may be weaker). The stronger adhesive at the perimeter may be 10% to 100% stronger than the weaker adhesive, or more particularly, 10% to 50%; or in an exemplary embodiment, 20% stronger. And moving in from the perimeter, the adhesive may gradually weaken until it becomes what may be termed the “weaker adhesive.” This gradient may be created by applying different amounts of adhesive across the surface of the adhesive layer, such that the perimeter has a greater amount of adhesive material than the interior or near the center of the adhesive layer, which may result in a stronger adhesive property.
In a further exemplary embodiment, a portion of the perimeter may have a weaker adhesive then other portions of the perimeter or than the rest of the perimeter. For example, a bottom end of the adhesive layer may have a weaker adhesive that is easier to separate from a user's skin, so as to allow the user to insert their finger at that portion under the adhesive layer and above the skin when it comes time to remove the adhesive layer from the skin. This portion may be arcuate in shape or in the shape of a fingertip. By allowing a user to insert their fingertip at this weaker adhesive portion when it comes time to remove the adhesive layer from the skin, it may be easier for the user to start the adhesive removal process of the rest of the adhesive layer.
In exemplary embodiments, an on-body medical device has an adhesive layer with adhesives of two or more strengths. In some of the exemplary embodiments, a stronger adhesive is positioned on the adhesive layer where additional strength is needed, such as around the perimeter of the adhesive layer to prevent premature peeling. A weaker adhesive is positioned on other portions of the adhesive layer where there is no need for the strength of the stronger adhesive. For example, the interior portion of the adhesive layer inside the perimeter may be coated with the weaker adhesive. The use of the weaker adhesive in the interior may reduce the discomfort to a user when peeling off the adhesive layer and may decrease the risk of skin damage. The stronger adhesive around the perimeter may still securely hold the adhesive layer to the skin of the user but may occupy only a thin band around the perimeter. As a result, it may not be as painful to peel off the adhesive layer of exemplary embodiments as it is to peel off a conventional adhesive layer with a strong adhesive coated on the entire adhesive layer since the band of stronger adhesive used in the exemplary embodiments only occupies a small surface area.
In other exemplary embodiments, at least three strengths of adhesives are used on the adhesive layer. An intermediate strength adhesive is used along with a stronger adhesive and a weaker adhesive. The stronger adhesive and weaker adhesive may be positioned largely as discussed above, but the intermediate strength adhesive may be used in areas where the weaker adhesive does not provide enough strength but the full strength of the stronger adhesive is not needed.
In some exemplary embodiments, the adhesives may be applied continuously over designated regions that cover large portions of the surface area of the adhesive layer. In other exemplary embodiments, one or more of the adhesives may be applied in small discrete regions, such as dots or islands, which may be surrounded by other adhesives on the adhesive layer. The discrete adhesive regions may be organized into a pattern, such as a grid. The discrete regions may provide discrete points or islands of stronger adhesive or discrete points or islands of weaker strength adhesive in exemplary embodiments.
More generally, the on-body medical device 100 is a device that is adhered to the user and serves a medical purpose. The on-body medical device 100 includes at least one housing 102 for housing components of the on-body medical device. The at least one housing may be positioned on or in a tray, which may previously have been attached to the skin of the user, and the tray may be attached to the adhesive layer. Alternatively, the at least one housing 102 may be attached to the adhesive layer as described in exemplary embodiments below. The at least one housing 102, may be made of a material, such as a plastic, a composite, a metal or a combination thereof. For example, suppose that the on-body medical device 100 is an insulin pump. In that case, the at least one housing 102 may house the mechanical and electrical components of the insulin pump, like an insulin reservoir, a microprocessor, a memory, a pump, batteries and the like. An adhesive layer 104 is secured to a surface of the on-body medical device 100. In
In some embodiments, the surface to which the adhesive layer 104 is secured is not part of the housing 102. Instead the surface may be part of a stand, feet or other element that is configured to be skin-facing (i.e., oriented to face the skin of the user). Accordingly, in some embodiments, the surface is an outer surface of the on-body medical device 100. That the surface is skin-facing does not require the surface to be in direct contact with the skin of the user, when the medical device 100 is attached to the user, in particular the adhesive layer 104 may be disposed between the surface and the skin 106 of the user. Moreover, there need not be a single adhesive layer. There may be multiple adhesive layers for multiple contact areas with the skin of the user.
Strength of the adhesives may be measured and classified in different ways. For example, the adhesives may be measured by peel strength. The peel strength may be determined for example according to ISO 8510-2:2006-12 or DIN EN 28510-1:2014-07. The peel strength may be expressed as N/mm. The adhesives strengths also may be measured and classified by how long the adhesive are intended to be adhered to the skin of a typical user experiencing typical use conditions. For example, an adhesive may be classified as a two day wear time adhesive if the adhesive is intended to securely hold for two days on the skin of a typical user with average skin properties (e.g., properties such as perspiration level at the particular skin surfaces where on-body medical devices are typically worn).
The stronger adhesive 316 may be 10% to 100% stronger than the weaker adhesive, or more particularly, 10% to 50%; or in an exemplary embodiment, 20% stronger than the weaker adhesive 318. The strength may be measured as peel strength or as wear time. “Wear time” may refer to an average wear time for a typical user (with typical skin properties) under typical use conditions. The peel strength of the stronger adhesive may be at least 20% stronger than the peel strength of the weaker adhesive 318 in an exemplary embodiment. Alternatively, the wear time of the stronger adhesive 316 may be at least 20% greater than the wear time of the weaker adhesive 318 in an exemplary embodiment. For example, the weaker adhesive may be a 1 or 2 day “wear time” adhesive, whereas the stronger adhesive may be a 3 or 4 day “wear time” adhesive, for an on-body medical device intended to be adhered to the user for 3 or 4 days. Thus, the stronger adhesive may be 50% or even 100% stronger in some instances, as suggested above.
As was mentioned above, the adhesive layer also may have more than two strengths of adhesives on it.
It should be appreciated that adhesives with more than three strengths may be applied to an adhesive layer. The number of adhesive strengths used on a particular adhesive layer may depend on the needs for a variety of adhesion strengths on the adhesive layer.
The adhesive layer need not be limited to having adhesives of different strengths applied to large continuous regions. Instead, an adhesive of a given strength may be applied to non-continuous discrete locations on the adhesive layer.
Alternatively, the islands 704 instead may be where the stronger adhesive is applied, and the area 702 may be where the weaker adhesive is applied or even no adhesive is applied. Moreover, in some embodiments, the islands 704 may be regions where no adhesive is applied and an intermediate strength adhesive or stronger strength adhesive is applied to region 702.
It may be desirable to put stronger adhesive around holes or other structures that protrude through the adhesive layer to prevent peeling of the adhesive layer at edges that surround such holes or structures.
In another exemplary embodiment, the adhesive may form a gradient of strength from an outer perimeter of the adhesive layer 900 where the adhesive may be stronger, and gradually weaken moving toward the center of the adhesive layer 900 where the adhesive typically doesn't need to be as strong since the interior portions may not experience the same stresses as the perimeter of the adhesive layer 900. An example of such a gradient of strength on the adhesive layer 900 is shown in
In a further exemplary embodiment as depicted in
While exemplary embodiments have been described herein, various changes in form and detail may be made without departing from the intended scope of the appended claims.
This application claims the benefit of U.S. Provisional Patent Application No. 63/371,776, filed Aug. 18, 2022, the entire contents of which are incorporated herein by reference in their entirety.
Number | Date | Country | |
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63371776 | Aug 2022 | US |