Intrusive Biosensor Alignment and Retention

Abstract

Describes examples of invasive biosensor alignment and retention features and methods. An exemplary biosensor includes: a housing that includes: a first surface defining a first opening, and a second surface opposite the first surface, the second surface defining a second opening, the first opening and the second opening defining a generally unobstructed passage through the housing; a biosensor wire that is partially disposed within the housing and has an external portion extending through the first opening; a hollow insertion needle that is positioned within the passage and extends through the first opening, the hollow insertion needle at least partially surrounding the biosensor wire; and a biosensor retention feature that is collapsible against the first surface of the housing, the biosensor retention feature surrounding and contacting the hollow insertion needle.

Description

Technical Field

[0001] This application generally relates to invasive biosensors and, more generally, to the alignment and retention of invasive biosensors. Background Art

[0002] Wearable invasive biosensors, such as continuous glucose monitors (“CGMs”), use sensor wires inserted into the skin of a wearer to measure analytes, such as glucose levels. Since sensor wires are typically small in diameter and may not be able to pierce the skin of the wearer without bending or breaking, a needle is used to create a puncture wound, and then the sensor wire is inserted through the puncture wound. In some cases, the needle is inserted through an opening in the biosensor and axially aligned with the sensor wire such that when the CGM is pressed against the skin of the wearer, the needle creates a puncture wound and inserts the sensor wire through the puncture. The needle is then withdrawn, leaving the sensor wire in place. Summary of the Invention

[0003] Various examples for the alignment and retention of invasive biosensors are described. An exemplary wearable biosensor includes: a housing that includes: a first surface defining a first opening, and a second surface opposite the first surface, the second surface defining a second opening, the first opening and the second opening defining a generally unobstructed passage through the housing; a biosensor wire that is partially disposed within the housing and has an external portion extending through the first opening; a hollow insertion needle that is positioned within the passage and extends through the first opening, the hollow insertion needle at least partially surrounding the biosensor wire; and a biosensor retention feature that is collapsible against the first surface of the housing, the biosensor retention feature surrounding and contacting the hollow insertion needle.

[0004] An exemplary method for providing alignment and retention of an invasive biosensor includes: providing a housing that includes: a first surface defining a first opening, and a second surface opposite the first surface, the first surface defining a second opening, the first opening and the second opening defining a generally unobstructed passage through the housing; positioning a biosensor wire within the housing and a first portion of the biosensor wire extending through the first opening; inserting a hollow insertion needle into the passage from the second opening, through the unobstructed passage and through the first opening, the hollow insertion needle at least partially surrounding the first portion of the biosensor wire; applying a biosensor retention feature to the hollow insertion needle, the biosensor retention feature surrounding and contacting the hollow insertion needle and configured to collapse against the bottom surface of the housing.

[0005] Another exemplary wearable biosensor includes: a housing that includes a first surface defining a first opening and a second surface opposite the first surface, the second surface defining a second opening, the first and second openings defining a generally unobstructed passage through the housing; a biosensor wire that is partially disposed within the housing and has an external portion extending through the first opening; a hollow insertion needle that is positioned within the passage and extends through the first opening that is coaxially aligned with the external portion of the biosensor, the hollow insertion needle at least partially surrounding the external portion of the biosensor wire; and means for maintaining coaxial alignment between the hollow insertion needle and the biosensor wire, the biosensor wire being coupled to a portion of the hollow insertion needle that is coaxially aligned with the external portion of the biosensor wire.

[0006] An exemplary method for applying a wearable biosensor includes: obtaining a wearable biosensor that includes: a housing that includes a first surface defining a first opening and a second surface opposite the first surface, the second surface defining a second opening, the first and second openings defining a generally unobstructed passage through the housing; a biosensor wire that is partially disposed within the housing and has an external portion extending through the first opening; a hollow insertion needle that is positioned within the passage and extends through the first opening, the hollow insertion needle at least partially surrounding the biosensor wire; and a biosensor retention feature that is collapsible against the first surface of the housing, the biosensor retention feature surrounding and contacting the hollow insertion needle; applying the wearable biosensor to the skin of a wearer includes: inserting the hollow insertion needle into the skin of the wearer through a puncture hole, inserting the biosensor wire through the puncture hole, and pressing the housing against the skin of the wearer and collapsing the biosensor retention feature against the housing; and withdrawing the hollow insertion needle from the skin and the housing of the wearer.

[0007] The mention of these illustrative examples is not intended to limit or define the scope of the present disclosure, but rather to provide examples to aid in its understanding. Illustrative examples are discussed in the detailed description, which provides further description. By examining this specification, the advantages provided by the various examples can be further understood. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The drawings incorporated in and forming a part of this specification illustrate one or more particular examples and, together with the description of the examples, are used to explain the principles and implementations of the particular examples.

[0009] Figures 1A to 1E An exemplary invasive biosensor and insertion needle and retention feature are shown;

[0010] Figures 2A to 2BShows exemplary biosensor alignment and retention features in accordance with the present disclosure;

[0011] Figure 3 Shows exemplary biosensor alignment and retention features in accordance with the present disclosure;

[0012] Figures 4A to 4B Shows exemplary biosensor alignment and retention features in accordance with the present disclosure;

[0013] Figures 5A to 5B Shows exemplary biosensor alignment and retention features in accordance with the present disclosure;

[0014] Figures 6 to 7 Shows exemplary manufacturing techniques for aligning a biosensor and inserting a needle in accordance with the present disclosure;

[0015] Figures 8A to 8B Shows an exemplary method for assembling biosensor alignment and retention features;

[0016] Figures 9A to 9B Shows an exemplary method for assembling biosensor alignment and retention features;

[0017] Figures 10A to 10B Shows an exemplary method for assembling biosensor alignment and retention features;

[0018] Figures 11A to 11B Shows exemplary biosensor alignment and retention features;

[0019] Figures 12A to 12B Shows exemplary biosensor alignment and retention features;

[0020] Figures 13A to 13B Shows exemplary biosensor alignment and retention features;

[0021] Figures 14A to 14C Shows exemplary biosensor alignment and retention features;

[0022] Figure 15 Shows an exemplary method for assembling biosensor alignment and retention features; and

[0023] Figure 16 Shows an exemplary method for applying a wearable biosensor having biosensor alignment and retention features. Detailed Description

[0024] The examples are described in the context of aligning and holding an invasive biosensor. Those of ordinary skill in the art will recognize that the following description is merely illustrative and not intended to be limiting in any way. Reference will now be made in detail to the embodiments of the examples illustrated in the accompanying drawings. The same reference numerals will be used throughout the drawings and the following description to refer to the same or like items.

[0025] For clarity, not all conventional features of the examples described herein are shown and described. Of course, it is understood that in developing any such actual embodiment, numerous implementation-specific decisions must be made in order to achieve the developer's specific goals, such as compliance with application- and business-related constraints, and such specific goals will vary from one implementation to another and will also vary from one developer to another.

[0026] An invasive biosensor includes one or more sensing components that are inserted into a human body, such as through a person's skin, and can measure an analyte to determine information such as glucose levels. For example, a continuous glucose monitor ("CGM") can be applied to a person ("wearer") and worn by the person for a period of time to monitor the wearer's glucose levels. This exemplary CGM includes a sensor wire that is inserted into the wearer's skin to access interstitial fluid and sense glucose levels. However, since the sensor wire is fragile at the expected thickness / diameter (100 micrometers (or μm) in this example), a needle is used to pierce the skin and insert the sensor wire. The exemplary CGM is coupled to an insertion device by a hollow insertion needle that is coaxially positioned with the CGM sensor wire within the hollow portion of the insertion needle. When the wearer applies the CGM, she will use the insertion needle to pierce the skin, and the sensor wire will follow the needle into the puncture site. After the CGM sensor wire has been inserted into the puncture and the CGM has been attached to the wearer's skin, the wearer withdraws the needle, leaving the sensor wire beneath the skin and the CGM in place.

[0027] Refer to Figures 1A to 1D , which illustrate different views of an exemplary CGM 100 having a housing 110 and a sensor wire 120. As Figure 1A can be seen, the sensor wire 120 extends out of the housing 110 such that it can be inserted into the wearer's skin, and the housing 110 can be attached to the wearer's skin.

[0028] To apply the CGM 100, as Figure 1BAs shown, the needle 130 (also referred to as the "insertion needle") is inserted through a hole in the upper surface of the CGM 100, through a cavity formed inside the CGM 100 for receiving the needle 130 and the sensor wire 120, and through a hole in the lower surface of the CGM 100. The needle 130 is inserted such that it is axially aligned with the sensor wire 120. Thus, the CGM 100, the needle 130, and the sensor wire 120 can all be pressed against the skin of the wearer to apply the CGM 100 in a single action. When the CGM 100 is pressed against the skin of the wearer, the needle 130 pierces the skin and the sensor wire 120 is pressed through the puncture hole. Then, the CGM 100 is pressed against the skin of the wearer and is retained there, for example, by a pressure-sensitive adhesive ("PSA"). Then, the needle 130 is withdrawn, leaving the CGM 100 and the sensor wire 120 in place.

[0029] Figures 1C to 1D Illustrated is how the needle 130 and the sensor wire 120 are joined to allow substantially simultaneous insertion into the skin of the wearer. In this example, the insertion needle 130 is hollow and has an open cross-section as Figure 1D shown, which can be referred to as having a "C" or "U" shape and extends slightly beyond the end of the sensor wire 120. The amount by which the needle extends beyond the sensor wire is not critical; however, piercing the skin of the wearer to a depth beyond that required to insert the sensor wire 120 should be avoided, as it can cause unnecessary pain or trauma to the wearer. As Figure 1D can be seen, the diameter of the cross-section of the needle is greater than the diameter of the sensor wire 120. By orienting and positioning the needle 130 to surround the sensor wire 120 within its hollow cross-section, the needle 130 and the sensor wire 120 can be coaxially positioned. Thus, when the wearer presses the needle 130 into the skin of the wearer to create a puncture hole, the sensor wire 120 can immediately travel into the puncture hole created by the needle 130.

[0030] However, in some examples, the CGM 100 can be packaged with the insertion needle 130 already coupled to the CGM 100. Thus, the user can obtain a new CGM 100 without having to insert the needle through the CGM 100 to apply the CGM 100 to it. However, since the packaged CGM 100 can be subject to various forces during manufacturing, packaging, and shipping, the sensor wire 120 and the needle 130 may become misaligned. For example, the sensor wire 120 may be jostled or bent out of the C-shaped cross-section, such as after the package has been dropped. To help maintain the coaxial arrangement of the needle 130 and the sensor wire 120 while subcutaneously inserting the sensor wire 120, the CGM 100 has sensor alignment and retention features coupled to its bottom surface.

[0031] Now refer to Figure 1E , Figure 1E which illustrates the bottom surface of the CGM 100 with attached sensor alignment and retention feature 140 (or "retention feature"). In this example, the retention feature 140 includes a portion that is adhered to the bottom surface of the CGM 100 via PSA. Additionally, the retention feature has an extensible portion 142 that has been cut and spiraled upward around the insertion needle 130. During manufacturing, the extensible portion 142 has been pulled away from the bottom surface of the CGM 100 to form a helical shape. The tip of the cut portion 142 contains a closely fitting hole that surrounds and engages the needle 130, thereby helping to prevent the sensor wire 120 from falling out of the cross-section of the hollow insertion needle 130. When the CGM 100 is later applied to the skin of a wearer, the extensible portion 142 collapses against the bottom surface of the CGM 100 and returns to a flat state as it is pressed against the skin of the wearer until it finally lies flush against the bottom surface of the CGM 100. Thus, the extensible portion 142 helps to maintain the coaxial alignment between the sensor wire 120 and the insertion needle 130 while not affecting the insertion process of the CGM.

[0032] This illustrative example is given to introduce the general subject matter discussed herein to the reader, and the present disclosure is not limited to this example. The following sections describe various other non-limiting examples as well as examples of systems and methods for invasive biosensor alignment and retention. Figures 2A to 14B Illustrative examples of devices for maintaining coaxial alignment between a hollow insertion needle and a biosensor wire are described and are described in more detail below.

[0033] Now refer to Figures 2A to 2B , Figures 2A to 2B which shows an exemplary sensor alignment and retention feature 210 according to the present disclosure. In this example, the retention feature 210 includes a pad (or backing material) 220 that can be used to couple the retention feature 210 to a biosensor, such as a CGM. The pad 220 can be shaped during manufacturing to correspond to the shape of the lower surface of the biosensor or a portion of the shape. The retention feature 210 also includes an expandable portion 230 that can extend during manufacturing or when the insertion needle is inserted through the CGM, thereby forming a helical feature to maintain coaxial alignment between the sensor wire and the insertion needle. In Figure 2A , the expandable portion has not yet extended and thus remains flush with the pad 220. This helps to illustrate the shape of the cut for forming the cut portion 230 and enables the cut portion to extend to form a helical shape.

[0034] In this example and during the manufacturing process, the gasket 220 is formed of polyurethane foam, but can also be constructed of other materials such as cloth, silicone, etc. In this example, the expandable portion 230 is formed of a sheet of material different from the gasket 220 and is joined to the gasket by an adhesive. However, in some examples, the expandable portion 230 can be formed of a sheet of the same material as the gasket 220. In some examples, as will be discussed in more detail below with respect to Figure 6 through 10, the gasket can be formed of multiple layers joined to each other. The expandable portion 230 can be formed of any suitable material, including polyurethane foam, silicone, etc. Additionally, in some examples, the retention feature may not include the gasket 220, but may alternatively include only the cut portion 230.

[0035] Figure 2B Illustrated is a retention feature 210 attached to the lower surface of the invasive biosensor 200. It can be seen that although the gasket 220 does not cover the entire bottom portion in this example, it generally corresponds to the shape of the bottom surface of the biosensor 200. It should be understood that the gasket 220 can have any suitable size and shape depending on the application. For example, during the manufacturing process, the shape and size of the gasket 220 can be set to match the shape and size of the bottom surface of the biosensor 200. In some examples, the gasket 220 can extend beyond one or more edges of the bottom surface of the biosensor 200, or can cover only a portion of the bottom surface of the biosensor 200.

[0036] Now referring to Figure 3 , Figure 3 shown is an exemplary sensor alignment and retention feature 310 (or simply "retention feature") in accordance with the present disclosure. In this example, the retention feature 310 includes an "accordion pleat" shape. During the manufacturing process, a length of material has been folded upon itself multiple times, and holes having a diameter tens of micrometers wider than the needle have been cut through the material to engage and surround the insertion needle 320. In this example, by engaging and surrounding the insertion needle 320, a sensor wire positioned within the hollow portion of the needle can be retained. If an impact or force is applied to the sensor wire, it can be retained in place within the hollow portion of the needle by the retention feature. Additionally, when the biosensor 300 is applied to a wearer, the retention feature 310 can be folded and collapsed against the bottom surface of the biosensor 300.

[0037] Although Figure 3 the example shown does not include a gasket, as discussed above with respect to Figures 2A to 2B , in some examples, the retention feature can also include or be joined to a gasket. As discussed above with respect to Figures 2A to 2BAs discussed in the examples of, any suitable gasket may be employed. Additionally, the retention feature 310 may be constructed separately and subsequently coupled to the gasket, or it may be formed from the same sheet of material as the gasket.

[0038] Now referring to Figures 4A to 4B , Figures 4A to 4B FIG. shows an exemplary sensor alignment and retention feature 420 (or simply "retention feature") in accordance with the present disclosure. In this example, the retention feature 420 is coupled to a gasket 410, which may be adhered to the lower surface of a biosensor 400 such as shown in Figure 4B FIG.. In this example, the retention feature 420 has a central feature 424 that engages and surrounds the insertion needle 430 of the biosensor 400. In the example shown in Figure 4A FIG., the central feature 424 does not yet have an opening, such as a hole or slit (e.g., in the shape of "|", "X", or "*"), cut therein to receive the insertion needle 430; however, the opening may be cut at any suitable time during the manufacturing process, or it may also be formed when the insertion needle is inserted through the CGM and the retention feature, which may occur during the manufacturing process or when the CGM is applied by the wearer.

[0039] In addition to the central feature 424, the exemplary retention feature 420 includes two legs 422a - b. Each leg 422a - b has two ends, one of which is coupled to the gasket 410, or if no gasket is used, a loop or other feature may be adhered to the bottom surface of the biosensor 400. The other end of each leg 422a - b is coupled to the central feature 424. In this example, the legs 422a - b are attached at opposite sides of the central feature 424 and are then each coupled to corresponding points on the gasket 410 that are approximately 180 degrees around the central feature 424, i.e., offset from each other by 180 degrees. In different examples, the legs may be coupled at different positions on the gasket 410 relative to the coupling points on the central feature 424, such as offset by 90 degrees, 120 degrees, etc. Additionally, although two legs 422a - b are shown in this example, in some examples, more than two legs may be employed. The two legs 422a - b allow the central feature 424 to extend away from the biosensor to engage and surround the insertion needle 430 at a position between the bottom surface of the biosensor 400 and the tip of the needle 430, as visible in Figure 4B FIG.. Additionally, when the biosensor 400 is applied to the skin of the wearer, the legs 422a - b allow the central feature 420 to collapse against its bottom surface.

[0040] Now referring to Figures 5A to 5B , Figures 5A to 5BIllustrates exemplary sensor alignment and retention feature 520 (or simply "retention feature") in accordance with the present disclosure. In this example, retention feature 520 is coupled to a pad 510 that may be attached during manufacturing to the lower surface of a biosensor, such as the biosensor 500 shown in Figure 5B . Similar to the example shown in Figure 4A , in this example, retention feature 520 has a central feature 524 that engages and surrounds the insertion needle 530 of biosensor 500. In the example shown in Figure 5A , the central feature 524 does not yet have an opening cut therein to receive the insertion needle 530; however, the opening may be cut at any suitable time during the manufacturing process. Alternatively, in some examples, the opening may be formed when the insertion needle is inserted through the CGM and retention feature, which may occur during the manufacturing process or when the CGM is applied by the wearer.

[0041] In addition to central feature 524, exemplary retention feature 520 includes two legs 522a-b. Similar to the example shown in Figure 4A , each leg 522a-b has two ends, one of which is coupled to pad 510, or if no pad is used, a loop or other feature may be attached to the bottom surface of biosensor 500. The other end of each leg 522a-b is coupled to central feature 524. In this example, legs 522a-b are attached at opposite sides of central feature 524 and are then each coupled at respective points on pad 510 that are offset from each other by approximately 90 degrees around central feature 424. As discussed above with respect to Figure 4A and 4B , any suitable number of legs may be employed in different examples. For example, the retention feature 520 shown in Figure 5A may be modified to add two additional legs, each of which may be coupled to central feature 524 such that each leg is coupled at a position offset from the other by 90 degrees, and the other end of each leg is likewise coupled at a position offset from the other by 90 degrees on pad 510.

[0042] In this example, the two legs 522a-b allow central feature 524 to extend away from biosensor 500 to engage and surround insertion needle 530 at a position between the bottom surface of biosensor 500 and the tip of needle 530, as visible in Figure 5B . Additionally, when biosensor 500 is applied to the skin of a wearer, legs 522a-b allow central feature 520 to collapse against its bottom surface. Thus, this exemplary retention feature 520 is capable of aligning and retaining the sensor wire within the hollow insertion needle 530 for application of the invasive biosensor 500.

[0043] Now refer to Figure 6 , Figure 6 which shows an exploded view of an exemplary gasket and sensor alignment and retention assembly 600. The exemplary alignment and retention assembly 600 includes four components that can be manufactured and assembled separately to provide sensor alignment and retention for an invasive biosensor. Assembly 600 includes a retention feature 610, a top layer adhesive 620, a backing material 630, and a bottom layer adhesive 640. In this example, the retention feature 610 has the same configuration as the retention feature 520 shown in Figures 5A to 5B which has two legs and a central feature. In this example, the retention feature 610 is manufactured from a single piece of polyurethane foam by cutting away portions of the foam to form the legs, the central feature, and the peripheral ring.

[0044] The top layer adhesive 620 is a PSA that is applied to the backing material 630 during the manufacturing process. The PSA is applied to the perimeter of the retention feature 610 and also to portions of the backing material 630 to provide adhesion between the backing material 630 and the bottom surface of the biosensor housing. In this example, the top layer adhesive 620 is provided as a single piece of double-sided tape, but in some examples it can be sprayed onto the backing material 630 or can include multiple pieces of tape. Additionally, the top layer adhesive 620 can be applied at any suitable location on the backing material 630 to provide adhesion between the backing material 630 and the retention feature 610 and between the backing material 630 and the bottom surface of the biosensor housing.

[0045] In this example, the backing material 630 is composed of a polyurethane-coated fabric; however, any suitable material such as cloth, foam, etc. can also be used. In this example, the backing material 630 is cut from a sheet of material into a shape corresponding to the shape of the housing of the biosensor and has holes corresponding to the retention features.

[0046] The bottom layer adhesive 640 is a PSA that is applied to the backing material 630 and is intended to adhere the backing material 630 and thereby the invasive biosensor to the skin of the wearer. Thus, the bottom layer adhesive 640 includes an adhesive suitable for long-term contact with human skin. Such an adhesive can be water-resistant and moisture-resistant. In this example, the adhesive includes a double-sided tape that has been cut into a shape corresponding to the shape of the backing material 630. In some examples, the bottom layer adhesive 640 can include another type of adhesive such as a liquid that can be sprayed onto the backing material 630 or can include multiple pieces of tape.

[0047] To create Figure 6The exemplary component 600 shown in the figure applies a top adhesive 620 to one side of a backing material 630. Then, the retention feature 610 is pressed against the backing material 630 at a position corresponding to the top adhesive 620 and the holes formed in the backing material 630. Then, a bottom adhesive 640 is applied to the other side of the backing material 630. It should be understood that the order of the above steps can vary according to different manufacturing processes. In some examples, other steps may be included, the above steps may be omitted, or the steps may be performed in a different order. For example, the backing material 630 with the top adhesive 620 and the retention feature 610 may be adhered to the bottom surface of the invasive biosensor before applying the bottom layer. Further variations are also within the scope of the present disclosure.

[0048] Now referring to Figure 7 , Figure 7 shows an exploded view of an exemplary gasket and a sensor alignment and retention assembly 700. In this example, the assembly includes a backing material 720 having a top adhesive 710 and a bottom adhesive 730.

[0049] Unlike Figure 6 the exemplary component 600 shown in the figure, in this example, the assembly has a retention feature 722 formed from the same piece of material as the backing material 720. Thus, unlike having two separate pieces, the backing material and the retention feature are formed from the same piece of material. Then, the top adhesive 710 can be applied to one side of the backing material 720 to adhere the backing material to the bottom surface of the invasive biosensor. The bottom adhesive 730 can be applied to the other side of the backing material 720 to adhere the backing material 720 to the skin of the wearer. Suitable materials for the backing material 720 and the retention feature 722, as well as suitable adhesives for the top adhesive 710 and the bottom adhesive 730, are described above.

[0050] Now referring to Figures 8A to 8B , Figures 8A to 8B illustrates an exemplary technique 800 for applying a retention feature to an invasive biosensor. In this example, an exemplary backing material (or gasket) and a sensor alignment and retention assembly similar to Figure 6 the component 600 shown in the figure are employed, but any other suitable component according to the present disclosure may also be used. Specifically, regarding Figures 8A to 8B the technique 800 described involves an assembly having different gaskets and retention features formed from different pieces of material.

[0051] In Figure 8AAt the frame 810a, as illustrated by the corresponding diagram 810b, the adhesive 852 is applied to the biosensor housing 850. In this example, the top layer adhesive 852 is a double-sided tape, which is cut into a shape corresponding to the shape of the bottom surface of the housing 850 and pressed onto the bottom surface of the housing 850. However, in some examples, the adhesive 852 can be sprayed onto the housing, the housing 850 can be dipped into the adhesive, or any other suitable technique can be used to apply the adhesive to the bottom surface of the housing 850, such as using heat fusion to fuse the components together. In this example, the adhesive 852 is applied to the entire bottom surface of the housing; however, in some examples, the adhesive 852 can be applied at positions corresponding to the retaining features 854 and at one or more other positions corresponding to the gasket 856 or a plurality of gaskets.

[0052] At the frame 820a, as illustrated by the corresponding diagram 820b, the retaining feature 854 is attached to the bottom surface of the housing 850 by pressing it onto the adhesive 852. The retaining feature 854 is applied at a position corresponding to where the sensor wire and the needle extend (or will extend) from the bottom surface of the housing 850, such that the opening on the retaining feature 934 is aligned with the exit point where the sensor wire exits from the bottom surface of the housing 850.

[0053] At the frame 830a, as illustrated by the corresponding diagram 830b, the gasket 856 is attached to the bottom surface of the housing 850 by pressing it onto the adhesive 852. In this example, the retaining feature 854 is not separately adhered to the gasket 856. Instead, the gasket 856 has a cutout corresponding to the retaining feature, such that the gasket 856 can be adhered to the housing 850 without interfering with the function of the retaining feature.

[0054] After attaching the gasket 856 to the bottom surface of the housing 850, an adhesive can be applied to the exposed surface of the gasket 856 to allow the gasket 856 to be attached to the skin of the wearer. This additional adhesive can be applied before or after attaching the gasket 856 to the housing 850. Additionally, this additional adhesive can be applied in the form of a tape or sprayed onto the gasket 856.

[0055] It should be understood that the order of the steps described above with respect to Figure 8A the method 800 can vary according to different manufacturing processes. In some examples, other steps can be included, the above steps can be omitted, or the steps can be performed in a different order. For example, the adhesive 852 can be applied to the retaining feature 854 and the gasket 856 separately, and they can be pressed onto the bottom surface of the housing 850. Further variations are also within the scope of the present disclosure.

[0056] Now refer toFigures 9A to 9B , Figures 9A to 9B Exemplary technique 900 for applying retention features to an invasive biosensor is illustrated. In this example, an exemplary gasket and sensor alignment and retention assembly similar to the Figure 6 exemplary assembly 600 shown is employed, but any other suitable assembly according to the present disclosure may also be used. Specifically, the technique 900 described Figures 9A to 9B relates to an assembly having different gaskets and retention features formed from different pieces of material.

[0057] At block 910a, as illustrated by corresponding diagram 910b, retention feature 934 is attached to the bottom surface of housing 930 by applying an adhesive to a portion of retention feature 932 and pressing retention feature 934 against the housing. For example, referring again to the Figure 6 retention feature 600 shown in, an adhesive 932 may be applied to the circumferential leg of the ring and one side of the central feature of the retention feature. Thus, retention feature 934 may be applied to the housing while allowing the leg and central feature to extend away from housing 930 and engage an insertion needle. After the adhesive 932 has been applied to retention feature 934, it may be attached to housing 930 by pressing it against housing 930. Retention feature 934 is applied to housing 930 at a location corresponding to where the sensor wire and needle extend (or will extend) from the bottom surface of housing 930 such that the holes or slots in retention feature 934 are aligned with the exit points where the sensor wires exit the bottom surface of housing 930.

[0058] At block 920a, as illustrated by corresponding diagram 920b, gasket 938 is attached to the bottom surface of housing 930 by applying an adhesive 936 to one side of gasket 938 and pressing it against the bottom surface of housing 930. In this example, gasket 938 has a cutout corresponding to retention feature 934 such that the gasket may be adhered to housing 930 without interfering with the function of the retention feature.

[0059] After attaching gasket 938 to the bottom surface of housing 930, an adhesive may be applied to the exposed surface of gasket 938 to allow gasket 938 to adhere to the skin of the wearer. This additional adhesive may be applied before or after attaching gasket 938 to housing 930. Additionally, this additional adhesive may be applied in the form of a tape or may be sprayed onto gasket 938.

[0060] It should be understood that the above regarding Figure 9AThe order of the steps described by method 900 can vary according to different manufacturing processes. In some examples, additional steps may be included, the above steps may be omitted, or the steps may be performed in a different order. For example, adhesive 932 can be applied to housing 930, and then retention feature 944 can be adhered to housing 930. Similarly, adhesive 936 can be applied to housing 930, and then gasket 938 can be pressed against the bottom surface of housing 850. Further variations are also within the scope of the present disclosure.

[0061] Now referring to Figures 10A to 10B , Figures 10A to 10B illustrates an exemplary technique 1000 for applying a retention feature to an invasive biosensor. In this example, an exemplary gasket and sensor alignment and retention assembly similar to Figure 6 the components 600 shown are employed, but any other suitable components according to the present disclosure can also be used. Specifically, with respect to Figures 10A to 10B the technique 1000 described involves an assembly having different gaskets and retention features formed from different pieces of material.

[0062] At block 1010a, gasket 1034 is attached to the bottom surface of housing 930. Adhesive 1032 can be applied to housing 1030, or it can be applied to gasket 1034. Then, it is attached to housing 1030 by pressing gasket 1034 against the bottom surface of housing 1030.

[0063] At block 1020a, as illustrated by corresponding diagrams 1020b and 1020c, a retention feature is applied to the biosensor. Regarding example 1020b, gasket 1034 is shaped to correspond to the shape of housing 1030, although it has portions that extend beyond the edges of housing 1030. Additionally, although gasket 1034 has openings cut therein to accommodate sensor leads and insertion needles, the retention feature is attached to gasket 1034 rather than housing 1030. In this example, an adhesive is applied to the bottom surface of the gasket, such as an adhesive suitable for adhering gasket 1034 to the skin of the wearer. Then, retention feature 1036 is pressed against the gasket and attached by the adhesive.

[0064] Regarding example 1020c, gasket 1035 is shaped to correspond to the shape of housing 1030, although it has portions that extend beyond the edges of housing 1030. Additionally, a portion is cut away from gasket 1035 to allow retention feature 1036 to be directly attached to housing 1030 by adhesive 1032. Retention feature 1036 is inserted into a cutout in gasket 1034, pressed against housing 1030, and attached by adhesive 1032.

[0065] The retention feature 1036 is applied to the housing 1030 at a position corresponding to where the sensor wire and the needle extend (or are to extend) from the bottom surface of the housing 1030 such that the opening in the retention feature 1036 is aligned with the exit point where the sensor wire exits from the bottom surface of the housing 1030. Additionally, after the gasket 1034 is attached to the bottom surface of the housing 1030, an adhesive can be applied to the exposed surface of the gasket 1034 to allow the gasket 1034 to adhere to the skin of the wearer. This additional adhesive can be applied before or after attaching the gasket 1034 to the housing 1030. Further, this additional adhesive can be applied in the form of a tape or can be sprayed onto the gasket 1034.

[0066] Now refer to Figures 11A to 11B , Figure 11A Examples A through B illustrate exemplary sensor alignment and retention feature 1110. In this example, the retention feature 1110 is a disk of material having an opening cut therein to allow the insertion needle and sensor wire to be inserted through the retention feature 1110. Different from the previous example, in this example, the retention feature 1110 is not attached to the housing or the gasket, but is positioned along the length of the insertion needle 1120 between the bottom of the invasive sensor 1100 and the tip of the needle 1120 and is fixed in place by a tight fit of the needle through the material. Thus, the retention feature 1110 engages and surrounds the needle 1120, thereby maintaining the sensor wire within the hollow portion of the sensor wire. Although in this example the retention feature 1110 has a circular shape, any suitable shape for the retention feature can also be employed.

[0067] Figure 11A Example A illustrates the retention feature 1110 mounted on the insertion needle prior to attaching the biosensor to the wearer. Figure 11B Example B illustrates how the retention feature 1110 collapses against the bottom surface of the biosensor 1100 after the biosensor has been attached to the wearer. This exemplary retention feature 1110 slides up along the needle 1120 until it presses against the underside of the biosensor.

[0068] Now refer to Figures 12A to 12B , Figure 12A Examples A through B illustrate exemplary sensor alignment and retention feature 1244. Figure 12AShown is a biosensor 1200 having a housing 1210, to which a gasket 1242 is adhered by an adhesive 1240. A sensor wire 1230 extends through a cavity defined in the housing 1210 and extends downwardly through a hole in the bottom surface of the housing 1210. Additionally, an insertion needle 1220 has been inserted through a hole defined in the upper surface of the housing 1210, through a cavity defined between holes in the upper and lower surfaces of the housing 1210, and out through the bottom of the biosensor 1200. As shown, a portion of the sensor 1230 is positioned within the hollow portion of the insertion needle 1220 such that the two are coaxially aligned.

[0069] In this example, a retention feature 1244 is shown as being similar to the Figures 11A to 11B retention feature 1110 shown in. Specifically, the retention feature 1244 engages the insertion needle 1220 but is not otherwise attached to the biosensor 1200. Instead, prior to attaching the biosensor 1200 to a wearer, the retention feature 1244 is positioned on the needle between the gasket 1242 and the tip of the needle 1220.

[0070] Figure 12B Illustrated is the biosensor 1200 after it has been applied to a wearer and the insertion needle 1220 has been withdrawn. The retention feature 1244 has been forced upward into contact with the gasket 1242, and the sensor wire 1230 has remained in place within the wearer's skin. Since the underside of 1242 is coated with an adhesive for attachment to the skin, the retention feature 1244 can adhere to the bottom of the gasket 1242. Thus, at a later time when the biosensor 1200 is removed, the retention feature 1244 will be removed with the biosensor 1200.

[0071] Now referring to Figures 13A to 13B , Figures 13A to 13B illustrates an exemplary sensor alignment and retention feature 1344. Figure 13A Shown is a biosensor 1300 having a housing 1310, to which a gasket 1342 is adhered by an adhesive 1340. A sensor wire 1330 extends through a cavity defined in the housing and extends downwardly through a hole in the bottom surface of the housing 1330. Additionally, an insertion needle 1320 has been inserted through a hole defined in the upper surface of the housing 1310, through a cavity defined between holes in the upper and lower surfaces of the housing 1310, and out through the bottom of the biosensor 1300. As shown, a portion of the sensor 1330 is positioned within the hollow portion of the insertion needle 1320 such that the two are coaxially aligned.

[0072] This example is similar to Figures 12A to 12BThe example shown, however, as can be seen in the figure, Figures 13A to 13B the gasket 1342 in Figures 13A to 13B has a cut-away portion to allow the retention feature to slide upward against the housing and be flush with the gasket 1342. Thus, after the biosensor 1300 has been attached to the skin of the wearer and the insertion needle 1320 has been removed, the retention feature 1344 has slid upward into the cut-out area within the gasket 1342, thereby making it flush with the gasket 1342 and adhered to the housing 1310 by the adhesive 1340. Thus, at a later time, when the biosensor 1300 is removed, the retention feature 1344 will be removed with the biosensor 1300.

[0073] Now refer to Figures 14A to 14C , Figures 14A to 14C illustrates an exemplary sensor alignment and retention feature 1430 in accordance with the present disclosure. In this example, the invasive biosensor 1400 includes sensor leads 1410 extending from the bottom surface of the biosensor 1400. The insertion needle 1420 has been inserted through the biosensor and is coaxially aligned with the sensor leads 1410. In this example, the retention feature 1430 has a plug-like shape with an opening formed therethrough to receive the insertion needle 1430 and is made of an elastomeric material such as silicone rubber or other.

[0074] The retention feature 1430 has a flat bottom surface 1432 that will be flush with the bottom surface of the biosensor 1400 once the biosensor 1400 has been attached to the skin of the wearer. It can be seen that, and similar to Figures 13A to 13B the disk 1344 shown in Figures 13A to 13B , the retention feature 1410 is attached to a portion of the insertion needle by an interference fit but is not otherwise attached to the biosensor 1400, as Figures 14A to 14B shown in Figures 14A to 14B . When the biosensor 1400 is applied to the skin of the wearer, the retention feature 1430 slides upward along the needle 1420 and into the cavity 1402 defined in the lower side of the biosensor 1400, thereby allowing the retention feature 1430 to collapse into and be retained by the biosensor 1400, as Figure 14C visible in Figure 14C .

[0075] Now refer to Figure 15 , Figure 15 shows an exemplary method 1500 for invasive biosensor alignment and retention in accordance with the present disclosure. Method 1500 will be described with respect to Figures 14A to 14B the exemplary retention feature 1430 shown in Figures 14A to 14B ; however, according to different examples, any suitable retention feature or device in accordance with the present disclosure may be employed.

[0076] At block 1510, a biosensor is obtained. In this example, the biosensor is obtained by constructing the biosensor. The biosensor is constructed by obtaining a housing having a first surface defining a first opening and a second surface opposite the first surface, the second surface defining a second opening, the first opening and the second opening defining a generally unobstructed passage through the housing.

[0077] After obtaining the housing, a biosensor wire is positioned within the housing and oriented such that a first portion of the biosensor wire extends through the first opening and out of the housing. Then, a hollow insertion needle is inserted through the second opening into the unobstructed passage and through the passage and through the first opening such that the hollow insertion needle at least partially surrounds the portion of the biosensor wire extending out of the housing.

[0078] At block 1520, a retention feature 1430 is obtained. For example, the retention feature 1430 can be received during a manufacturing process, such as by an automated machine operating as part of an assembly line. In one example, the retention feature 1430 is picked up by a robotic arm. In some examples, the retention feature 1430 can be provided in an uncut sheet of material having one or more preformed retention features 1430.

[0079] At block 1520, the retention feature 1430 is attached to the needle 1420 of the biosensor 1400. In this example, and as described above, the needle 1420 is inserted through the housing of the biosensor 1430, such as through a hole in the upper surface of the biosensor 1400, through a cavity formed within the biosensor 1420, and out through a hole in the lower surface of the biosensor 1400. Additionally, the needle 1420 is coaxially aligned with a sensor wire 1410 that is mounted within the biosensor but extends downward through a hole in the bottom surface of the biosensor 1400 and is positioned within the hollow portion of the needle 1420.

[0080] In this example, the opening formed on the retention feature 1430 is aligned with the needle 1420, and the retention feature 1430 is pressed onto the needle 1420 and slides along a portion of the length of the needle 1420. The distance that the retention feature 1430 slides along the length of the needle 1420 may vary according to different examples, however, in this example, the retention feature 1430 is ultimately positioned to allow approximately 1 to 5 mm of the needle 1420 (including the sharp tip of the needle 1420) to protrude from the retention feature 1430. In some examples, the retention feature 1430 may be positioned so that no portion of the needle 1420 protrudes from the retention feature 1430, but the sharp tip of the needle 1420 is generally aligned with the flat bottom surface 1432 of the retention feature 1430. Such positioning can provide sensor alignment and retention functions, and can also shield the end of the needle 1420 to prevent it from accidentally contacting the wearer or some other object before being inserted into the wearer's skin.

[0081] In this example, needle 1420 is pressed through a hole formed on retention feature 1430; however, in some examples, a retention feature may be formed without such a hole. Thus, the needle may be pressed through the retention feature to form a hole and couple the retention feature to the needle.

[0082] In some examples, at block 1520, retention features 1430 may be applied, as described above with respect to Figures 8A to 8B , Figures 9A to 9B or Figures 10A to 10B Other components described, such as one or more adhesives or gaskets.

[0083] In some examples, such as regarding Figures 11A to 11B , Figures 12A to 12B or Figures 13A to 13B In the example shown in , the retaining feature 1430 discussed above can be replaced with a disk, such as Figures 11A to 11B In addition, the disk 1110 shown in FIG. Figures 8A to 8B , Figures 9A to 9B or Figures 10A to 10B As discussed in methods 800 to 1000, applying one or more liners or adhesives, such as Figures 12A to 12B and Figures 13A to 13B as shown in .

[0084] Reference now Figure 16 , Figure 16 A method 1600 for applying a wearable biosensor with a biosensor retention feature is shown. Figure 16 The exemplary method will be about Figures 11A to 11B ; however, any suitable wearable biosensor and biosensor retention features consistent with the present disclosure may be employed.

[0085] At block 1610, the wearer obtains a wearable biosensor 1100 having a biosensor retention feature 1110 that surrounds and contacts a hollow insertion needle that is inserted through the housing of the biosensor and is coaxially aligned with a portion of a sensor wire extending from the housing of the biosensor.

[0086] At block 1620, the wearer applies the wearable biosensor 1100 by inserting the hollow insertion needle 1120 through a puncture at a desired location on the wearer's skin. The wearer also inserts the biosensor wire through the puncture by collapsing a biosensor securing member against the housing by pressing the housing of the wearable biosensor against the wearer's skin, taking advantage of the coaxial alignment between the biosensor wire and the hollow insertion needle 1120.

[0087] At block 1630, the wearer withdraws the insertion needle from the puncture and the housing, leaving the wearable biosensor affixed to the wearer's skin and the biosensor wire inserted through the patient's skin.

[0088] The foregoing description of some examples is given for illustrative and descriptive purposes only and is not exhaustive or intended to limit the disclosure to the precise forms disclosed. Many modifications and adaptations will be obvious to those skilled in the art without departing from the spirit and scope of the disclosure.

[0089] The reference herein to an example or embodiment means that a particular feature, structure, operation, or other characteristic described in connection with the example can be included in at least one embodiment of the disclosure. The disclosure is not limited to the particular examples or embodiments so described. The appearance of the phrases "in one example," "in an example," "in one embodiment," or "in an embodiment," or variations thereof in various places in the specification are not necessarily all referring to the same example or embodiment. Any particular feature, structure, operation, or other characteristic described in connection with one example or embodiment can be combined with other features, structures, operations, or other characteristics described in connection with any other example or embodiment.

[0090] The word "or" as used herein is intended to cover both inclusive and exclusive OR conditions. In other words, A or B or C includes any and all of the following alternative combinations as appropriate for a particular use: only A; only B; only C; only A and B; only A and C; only B and C; and A and B and C.

Claims

1. A wearable biosensor, comprising: A housing, comprising: A first surface defining a first opening, and A second surface opposite the first surface, the second surface defining a second opening, the first opening and the second opening defining a generally unobstructed passage through the housing; A biosensor wire, partially disposed within the housing and having an external portion extending through the first opening; A hollow insertion needle, positioned within the passage and extending through the first opening, the hollow insertion needle at least partially surrounding the biosensor wire; and A biosensor retention feature capable of collapsing against the first surface of the housing, the biosensor retention feature surrounding and contacting the hollow insertion needle.

2. The wearable biosensor according to claim 1, wherein the biosensor retention feature comprises a patch, an inner ring member, an outer ring member, and at least one flexible leg member coupling the inner ring member to the outer ring member, The inner ring member surrounds and contacts the hollow insertion needle, The outer ring member is attached to the patch, and The patch is attached to the first surface of the housing.

3. The wearable biosensor according to claim 2, wherein the biosensor retention feature comprises a plurality of flexible leg members coupling the inner ring member to the outer ring member, each of the flexible leg members being attached to the inner ring member at a respective first contact point and to the outer ring member at a respective second contact point.

4. The wearable biosensor according to claim 3, wherein the respective first contact point and second contact point for at least one flexible leg member are offset from each other.

5. The wearable biosensor according to claim 1, wherein the biosensor retention feature comprises a disk defining a hole, the insertion needle and the biosensor wire extending through the hole in the disk, the disk being spaced apart from the first surface of the housing.

6. The wearable biosensor according to claim 5, wherein the biosensor retention feature comprises a flexible material.

7. The wearable biosensor according to claim 6, wherein the flexible material comprises a polyurethane foam material or a silicone material.

8. The wearable biosensor according to claim 5, wherein the biosensor retention feature is adapted to cause the disk to slide along the hollow insertion needle and contact the first surface of the housing in response to a force applied to the first surface of the disk.

9. The wearable biosensor according to claim 1, wherein the biosensor retention feature comprises a plug-shaped member defining a hole extending through the plug-shaped member, the insertion needle and the biosensor wire extending through the hole in the plug-shaped member.

10. The wearable biosensor according to claim 9, wherein the plug-shaped member is configured to slide along the hollow insertion needle and into an opening defined in the first surface of the housing in response to a force applied to the first surface of the plug-shaped member.

11. The wearable biosensor according to claim 1, further comprising a gasket attached to the first surface of the housing, the retaining feature being coupled to the gasket and extending away from the gasket.

12. The wearable biosensor according to claim 1, further comprising a gasket attached to the first surface of the housing, the retaining feature not being coupled to the gasket, the gasket defining a cutout portion corresponding to the retaining feature, the retaining feature being configured to collapse against the housing and enter the cutout portion defined by the gasket.

13. A method of assembling a wearable biosensor, comprising: providing a housing including: a first surface defining a first opening, and a second surface opposite the first surface, the second surface defining a second opening, the first opening and the second opening defining a generally unobstructed passage through the housing; positioning a biosensor wire within the housing and a first portion of the biosensor wire extending through the first opening; inserting a hollow insertion needle through the second opening and through the unobstructed passage and through the first opening, the hollow insertion needle at least partially surrounding the first portion of the biosensor wire; applying a biosensor retaining feature to the hollow insertion needle, the biosensor retaining feature surrounding and contacting the hollow insertion needle and being configured to collapse against the first surface of the housing.

14. The method according to claim 13, wherein the biosensor retaining feature includes a gasket, an inner ring member, an outer ring member, and at least one flexible leg member coupling the inner ring member to the outer ring member, and wherein applying the biosensor retaining feature to the hollow insertion needle includes: sliding the inner ring member onto the hollow insertion needle and contacting it, attaching the outer ring member to the gasket, and attaching the gasket to the first surface of the housing.

15. The method according to claim 13, wherein the biosensor retaining feature includes a disk defining a hole, and wherein applying the biosensor retaining feature to the hollow insertion needle includes sliding the disk onto the insertion needle and contacting it.

16. The method according to claim 15, wherein sliding the disk onto the insertion needle and contacting it includes leaving an air gap between the disk and the first surface of the housing.

17. The method according to claim 13, wherein the biosensor retaining feature includes a plug-shaped member, the plug-shaped member defining a hole extending through the plug-shaped member, and wherein applying the biosensor retaining feature to the hollow insertion needle includes sliding the plug-shaped member onto the insertion needle and contacting it.

18. The method according to claim 13, wherein applying the biosensor retaining feature to the hollow insertion needle includes forming a hole in the biosensor retaining feature by pressing the tip of the hollow insertion needle through the biosensor retaining feature.

19. The method according to claim 13, wherein the biosensor retention feature comprises a patch and a helical member, and applying the biosensor retention feature to the hollow insertion needle comprises: attaching the patch to the first surface of the housing; surrounding the hollow insertion needle with the helical member; and extending the helical member along the length of the hollow insertion needle and away from the patch.

20. A method of applying a wearable biosensor, comprising: obtaining a wearable biosensor, the wearable biosensor comprising: a housing including a first surface defining a first opening and a second surface opposite the first surface, the second surface defining a second opening, the first opening and the second opening defining a generally unobstructed passage through the housing; a biosensor wire partially disposed within the housing and having an external portion extending through the first opening; a hollow insertion needle positioned within the passage and extending through the first opening, the hollow insertion needle at least partially surrounding the biosensor wire; and a biosensor retention feature capable of collapsing against the first surface of the housing, the biosensor retention feature surrounding and contacting the hollow insertion needle; applying the wearable biosensor to the skin of a wearer comprising: inserting the hollow insertion needle into the skin of the wearer through a puncture; inserting the biosensor wire through the puncture, and pressing the housing against the skin of the wearer and causing the biosensor retention feature to collapse against the housing; and withdrawing the hollow insertion needle from the skin of the wearer and the housing.

21. The method according to claim 20, wherein the biosensor retention feature comprises a patch, an inner ring member, an outer ring member, and at least one flexible leg member coupling the inner ring member to the outer ring member, the inner ring member surrounding and contacting the hollow insertion needle, the outer ring member being attached to the patch, and the patch being attached to the first surface of the housing.

22. The method according to claim 20, wherein the biosensor retention feature comprises a disk defining a hole, the insertion needle and the biosensor wire extending through the hole in the disk, the disk being spaced apart from the first surface of the housing.

Images