Retraction, actuation, deployment, and integration of flexible elongated elements

Abstract

Exemplary embodiments provide methods, devices, and support structures for deploying a flexible, elongate element (e.g., a conduit or subcutaneous sensor) into a user's tissue (e.g., skin tissue). A first embodiment utilizes rotational motion to deploy the element while constraining it to prevent buckling. A second embodiment utilizes linear motion to deploy the flexible, elongate element with the assistance of an introducer element to provide support. Other embodiments provide support features, such as a sacrificial sleeve, which can temporarily hold or encase the elongate element and temporarily increase the structural rigidity of the elongate element. Other support structures may provide tensioning of the user's tissue, for example, by bulging the skin in the area where deployment of the elongate element is facilitated. The cannula or sensor itself may also be structured or configured to support deployment.

Description

[Technical Field]

[0001] (CROSS-REFERENCE TO RELATED APPLICATIONS) This application claims priority to and the benefit of U.S. Provisional Patent Application No. 63 / 434,243, filed December 21, 2022, the entire contents of which are incorporated herein by reference. [Background technology]

[0002] Advances in miniaturization have enabled the creation of body-wearable devices capable of administering therapeutic drugs and sensing and reporting physiological characteristics. Examples of such devices include, but are not limited to, devices for administering insulin, glucagon-like peptide 1 (GLP-1), a combination of insulin and GLP-1, fertility drugs, leukocyte stimulating drugs, or other medications.

[0003] Such devices typically deploy a needle, conduit, cannula, or other element that connects the body-worn device into the user's tissue (e.g., skin). Such deployable elements are generally referred to herein as "conduits," although it should be understood that the term conduit encompasses needles, cannulae, and other similar deployable elements. To determine how much therapeutic agent to administer, the device may include a sensor (e.g., a glucose or ketone sensor), which may be part of the conduit or separate from it.

[0004] The conduit must be large enough to effectively provide the above functions, but preferably is as small as possible given those constraints. A smaller conduit generally means less pain for the user, both when the element penetrates the skin and during extended deployment (as may be necessary for automatic insulin delivery or "AID" devices). It also means that the overall device can be smaller, allowing it to be worn discreetly under clothing and improving the user's comfort while wearing it.

[0005] At the same time, the conduit must be sufficiently stiff to penetrate the skin without buckling. As these conduits become narrower or more flexible and / or elongated, they tend to have insufficient stiffness due to the inherent physical properties of the material (e.g., elastic modulus) and very small physical size and geometry (e.g., geometric cross-sectional stiffness). Thin, flexible, elongated elements naturally have low geometric stiffness and are notoriously difficult to deploy to adequate penetration depths in deformable materials such as human skin tissue. They instead tend toward structural compromise due to axial compressive forces, which can result in undesirable lateral displacement of the structure (e.g., buckling or flexing due to rebounding off the top surface of the skin and failure to penetrate, such as when the conduit is inserted at an angle) under critical load conditions or upon insertion or penetration through human skin. Summary of the Invention

[0006] The exemplary embodiments provide a unique conduit deployment assembly configured to mitigate deployment failure during an insertion event and enable proper functional use after initial insertion.

[0007] In one aspect, the device includes a deployable element configured to be deployed subcutaneously; a rotation mechanism having a periphery around at least a portion of which the deployable element is wrapped, the rotation mechanism configured to rotate the deployable element about the periphery; and a base having an opening configured for the deployable element to extend through, wherein the deployable element is selectively constrained such that rotation of the deployable element is converted into linear motion.

[0008] In some embodiments, the rotation mechanism may be a sheave or flywheel assembly.

[0009] The device may also include a torsion spring configured to provide energy to rotate the rotation mechanism.

[0010] The device may also include a stop plate configured to control the extent to which the deployable element extends beyond the opening.

[0011] The device may also include a fluid conduit configured to connect the deployable element to the reservoir.

[0012] The use of a rotation mechanism as described above may allow the device to be effective while remaining relatively small (i.e., less than about 0.5 inches by 0.5 inches by 0.375 inches (about 12.7 mm by 12.7 mm by 9.53 mm)).

[0013] The deployable element can be selected from the group consisting of a cannula, a conduit, a needle, or a sensor, hi some embodiments, the deployable element is a glucose sensor configured to perform continuous glucose monitoring or a ketone sensor.

[0014] The device may also include at least one housing configured to house the device. In some embodiments, the device deploys a sensor and the at least one housing houses only the device. In other embodiments, the device may be part of an automatic insulin delivery (AID) device, and the at least one housing houses both the device and the AID device.

[0015] The device may also include at least one convex or concave protrusion on the base, wherein the protrusion is sized and shaped to tension the user's skin near the opening when the base is pressed or applied against the skin.

[0016] In some embodiments, the deployable element has a circular cross-section (e.g., a laminated or coated wire). In others, the deployable element may have a rectangular cross-section (as may be the case in a conduit). In some embodiments, the deployable element has a laminated construction including at least one polymer, at least one metal, and a coating. In some embodiments, the deployable element comprises one or more conductive signal traces connected to embedded electronic hardware.

[0017] In another aspect, the device includes a deployable element extending linearly in a first direction and configured to be deployed subcutaneously, an introducer extending in the first direction parallel to the deployable element, a base having an opening through which the deployable element is configured to extend, and a linear deployment mechanism configured to extend the deployable element and the introducer in the first direction.

[0018] The introducer may include a geometric interface having an angled structure, and further includes a suspension portion having a suspension opening through which the deployable element and introducer pass, where the suspension opening is shaped such that the deployable element can remain on its original linear path until an established stopping point is reached and the introducer receives a force releasing the introducer from the driving force of the linear deployment mechanism due to the angled structure leading to a portion of the suspension opening.

[0019] The device may also include a tension spring connected to one end of the introducer, wherein the tension spring is configured to reverse the direction of displacement of the introducer to secure the sharp end of the introducer within the protected structure.

[0020] The device may also include a sacrificial sleeve that couples the deployable element and the introducer.

[0021] Other technical features will be readily apparent to those skilled in the art from the following figures, descriptions, and claims.

[0022] To easily identify the discussion of a particular element or function, the most significant digit(s) in a reference number refer to the figure number in which that element is first introduced. [Brief explanation of the drawings]

[0023] [Figure 1A] FIG. 1A is a perspective view of an exemplary rotating cannula deployment mechanism according to a first embodiment. [Figure 1B] FIG. 1B is a side view of an exemplary rotating cannula deployment mechanism according to a first embodiment. [Figure 1C] FIG. 1C is a perspective view of an exemplary rotating cannula deployment mechanism according to a second embodiment. [Figure 1D] FIG. 1D illustrates an exemplary damper suitable for use with the exemplary embodiment. [Figure 1E]FIG. 1E illustrates an internal view of an exemplary damper suitable for use with exemplary embodiments. [Figure 1F] FIG. 1F is a side view of an exemplary rotating cannula deployment mechanism with a damper. [Figure 2] FIG. 2 is a perspective view showing the sheave assembly in a first, undeployed state. [Figure 3] FIG. 3 is a perspective view showing the sheave assembly in a second deployed state. [Figure 4A] FIG. 4A provides a close-up view of one of the sheave assemblies of the first embodiment. [Figure 4B] FIG. 4B provides a close-up view of one of the sheave assemblies of the first embodiment. [Figure 4C] FIG. 4C provides a close-up view of one of the sheave assemblies of the first embodiment. [Figure 4D] FIG. 4D provides a close-up view of one of the sheave assemblies of the first embodiment. [Figure 5] FIG. 5 provides various views of the deployment mechanism of the first embodiment housed within a stand-alone housing. [Figure 6] FIG. 6 provides various views of the deployment mechanism of the first embodiment housed within a housing that can house other components such as an automatic insulin delivery (AID) device. [Figure 7A] FIG. 7A is an exploded perspective view of an exemplary rotating cannula deployment mechanism according to a first embodiment. [Figure 7B] FIG. 7B shows a perspective view from the opposite side compared to FIG. 8A. [Figure 8] FIG. 8 is a side view showing the deployable element 102 of the first embodiment in more detail. [Figure 9] FIG. 9 is a side view illustrating an alternative configuration for the deployable element 102 of the first embodiment. [Figure 10A] FIG. 10A is a front and side perspective view showing the sheave assembly of the first embodiment in more detail. [Figure 10B] FIG. 10B is a side and rear perspective view showing the sheave assembly of the first embodiment in more detail. [Figure 11] FIG. 11 is a perspective view showing the electrical connections between the sensor and the on-board front-end electronics, and the electrical service loop for connecting the front-end electronics to the back-end electronics in the drug delivery device body. [Figure 12A] FIG. 12A illustrates an alternative release mechanism suitable for use with the exemplary embodiment. [Figure 12B] FIG. 12B illustrates an alternative release mechanism suitable for use with the exemplary embodiment. [Figure 12C] FIG. 12C illustrates an alternative release mechanism suitable for use with the exemplary embodiment. [Figure 12D] FIG. 12D illustrates an alternative release mechanism suitable for use with the exemplary embodiment. [Figure 13] FIG. 13 is an exploded perspective view of an exemplary linear cannula deployment mechanism according to a second embodiment. [Figure 14] FIG. 14 is a side, bottom perspective view of the assembled linear cannula deployment mechanism of the second embodiment in a first, undeployed state. [Figure 15] FIG. 15 is a side, bottom perspective view of the assembled linear cannula deployment mechanism of the second embodiment in a second deployed state. [Figure 16] FIG. 16 shows the second embodiment introducer in more detail. [Figure 17] FIG. 17 is a side view of a structure for tensioning a user's epidermis, suitable for use with any of the described embodiments. [Figure 18] FIG. 18 is a side view of an alternative skin tensioning structure suitable for use with any of the described embodiments. [Figure 19] FIG. 19 is a perspective view of the skin tension structure. [Figure 20]FIG. 20 is a side view of the skin tensioning structure of FIG. 17 showing different possible protrusion profile shapes. [Figure 21A] FIG. 21A is a perspective view showing an exemplary cannula configuration suitable for use with any of the described embodiments. [Figure 21B] FIG. 21B illustrates one aspect of the subject matter according to one embodiment. [Figure 21C] FIG. 21C illustrates one aspect of the subject matter according to one embodiment. [Figure 22] FIG. 22 is a side view of the exemplary cannula structure of FIG. 21A. [Figure 23] FIG. 23 is a perspective view illustrating an exemplary sensor structure suitable for use with any of the described embodiments. [Figure 24A] FIG. 24A shows an exemplary rotating cannula deployment mechanism that utilizes an introducer to penetrate the outermost layer of the skin. [Figure 24B] FIG. 24B shows the rotating cannula deployment mechanism of FIG. 24A with an exemplary cowling. [Figure 25A] FIG. 25A illustrates an exemplary introducer suitable for use with the rotating cannula deployment mechanism of FIG. 24A. [Figure 25B] FIG. 25B illustrates an exemplary introducer suitable for use with the rotating cannula deployment mechanism of FIG. 24A. [Figure 26A] FIG. 26A illustrates an exemplary introducer according to one embodiment. [Figure 26B] FIG. 26B illustrates an exemplary introducer according to one embodiment. [Figure 26C] FIG. 26C illustrates an exemplary introducer according to one embodiment. [Figure 27A] FIG. 27A shows how the introducer is positioned relative to the cowling features in an exemplary rotating cannula deployment mechanism. [Figure 27B] FIG. 27B provides a view of a sheave for a rotating cannula deployment mechanism. [Figure 27C] FIG. 27C provides a diagram of a sheave for a rotating cannula deployment mechanism. [Figure 28A] FIG. 28A shows an exemplary retaining block for use with a rotating cannula deployment mechanism in one stage of assembly. [Figure 28B] FIG. 28B shows an exemplary retaining block for use with a rotating cannula deployment mechanism in one stage of assembly. [Figure 28C] FIG. 28C shows an exemplary retaining block for use with a rotating cannula deployment mechanism in one stage of assembly. [Figure 28D] FIG. 28D shows an exemplary retaining block for use with a rotating cannula deployment mechanism in one stage of assembly. [Figure 29A] FIG. 29A shows the rotating cannula deployment mechanism with the introducer moving through one stage of deployment and retraction. [Figure 29B] FIG. 29B shows the rotating cannula deployment mechanism with the introducer moving through one stage of deployment and retraction. [Figure 29C] FIG. 29C shows the rotating cannula deployment mechanism with the introducer moving through one stage of deployment and retraction. [Figure 30A] FIG. 30A shows the rotating cannula deployment mechanism in a pre-deployed state. [Figure 30B] FIG. 30B shows the rotating cannula deployment mechanism in a fully inserted state. [Figure 31] FIG. 31 illustrates the interface between the introducer and the spring, according to an exemplary embodiment. [Figure 32A] FIG. 32A is a side view showing the rotating cannula deployment mechanism in a pre-deployed state. [Figure 32B] FIG. 32B is a side view showing the rotating cannula deployment mechanism in a fully inserted state. DETAILED DESCRIPTION OF THE INVENTION

[0024] The illustrative embodiments provide methods, devices, and support structures for deploying a flexible, elongated element (eg, a conduit or a subcutaneous sensor) into a user's tissue (eg, skin tissue).

[0025] A first embodiment utilizes rotational motion to deploy the element while constraining it to prevent buckling, which may allow the element to be deployed without the aid of an introducer element to support the flexible element.

[0026] By utilizing rotational motion from an available, harnessed potential energy source (e.g., a torsion spring) and a force moment applied to a thin element selectively constrained to the radius of a flywheel or sheave, the thin element is guided from circumferential to linear motion with minimal frictional resistance and forced into the skin tissue layer by the distal, sharp end of the elongated element. Such circumferential wrapping and initial retraction provides a method for tightly encapsulated (minimal spatial volume mechanism) deployment of the sensor element to a depth of the subcutaneous tissue below the outer surface of the skin (in some embodiments, approximately 4-7 mm).

[0027] A second embodiment utilizes linear motion to deploy a flexible, elongated element with the assistance of an introducer element to provide support. Using linear motion derived from an accessible, controlled potential energy source (e.g., a helical compression spring) and force applied to a selectively constrained configuration of one or more thin elements, the thin elements are guided in a linear motion with minimal frictional resistance and forced into the skin tissue layer starting at the distal, sharp end of the elongated element (in this embodiment, a subcutaneous introducer). Such linear retraction provides a method for tightly encapsulated (minimal spatial volume) deployment of the sensor element to a depth of subcutaneous tissue (4-7 mm) below the outer surface of the skin.

[0028] Other embodiments provide support features that improve the functionality of the above embodiments, for example, a sacrificial sleeve may temporarily hold or encase the elongate element, temporarily increasing the structural rigidity of the elongate element.

[0029] Other support structures may provide tensioning of the user's tissue, for example by bulging the skin in the area where deployment of the elongate elements is facilitated. This structure may include a protruding annular structure on the body-worn or body-adhered device that contacts and / or adheres to the skin upon insertion of the deployed elongate elements into the human skin layer.

[0030] The cannula or sensor itself may also be structured or configured to support deployment. For example, laminated compositions of polymers, metals, and other materials may be combined into various cross-sectional shapes. These elements may be employed to develop desired directional stiffness for improved deployment penetration and / or to maintain conductive signal conduits / traces to embedded electronic hardware.

[0031] Illustrative Embodiments To aid in understanding, a series of examples are first presented before providing a detailed description of the underlying implementations. It should be noted that these examples are intended to be illustrative only, and the present invention is not limited to the embodiments shown.

[0032] Reference will now be made to the drawings, wherein like reference numerals are used to refer to like elements throughout. In the following description, for purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding thereof. However, novel embodiments may be practiced without these specific details. In other instances, well-known structures and devices are shown in block diagram form to facilitate description. The intention is to cover all modifications, equivalents, and alternatives consistent with the claimed subject matter.

[0033] In the drawings and accompanying description, the designators "a," "b," and "c" (and similar designators) are intended to be variables that take on any positive integer value. Thus, for example, if one implementation sets the value a=5, then the complete set of components 122, shown as components 122-1 through 122-a, may include components 122-1, 122-2, 122-3, 122-4, and 122-5. Embodiments are not limited in this context.

[0034] (Introducer-less rotating cannula deployment mechanism) The first embodiment provides an introducer-less, rotating conduit deployment assembly 100, as shown in Figures 1A-4D. The conduit deployment assembly 100 can be used to deploy a conduit, a sensor, or both (as desired).

[0035] 1A and 1B show an assembled conduit deployment assembly 100. The conduit deployment assembly 100 includes a deployable element 102, which may be a cannula, needle, conduit, sensor, or the like. For example, the deployable element 102 may be a cannula or needle for delivering a medication such as insulin. The deployable element 102 may be a glucose sensor or a ketone sensor (e.g., an electrochemical sensor, a fiber optic sensor, a wire sensor, an optofluorescence sensor, etc.), a temperature sensor, or an activity sensor. In some embodiments, multiple sensors can be combined into a single deployable element 102, such as may be the case when one side of the deployable element 102 serves as a glucose sensor and the opposite side serves as a ketone sensor.

[0036] In this example, the deployable element 102 rotates along the outer radius of the flywheel or sheave until the rotational motion is converted into linear motion and the deployable element 102 moves linearly in and out of an opening 114 in the base 108 that supports the conduit deployment assembly 100 (e.g., on the user's skin). The deployable element 102 may be selectively constrained by a cowling 104 that surrounds the deployable element 102 and the sheave. Additionally or alternatively, the cowling 104 may take the form of a housing for the conduit deployment assembly 100.

[0037] The conduit deployment assembly 100 is positioned and / or held on the base 108 using one or more base protrusions 126 and / or ribs 128 that fit into corresponding notches in the bottom of the cowling 104, and the cowling 104 may be flared outward to allow connection between the conduit deployment assembly 100 and the base 108.

[0038] Using rotational motion derived from an available and controlled potential energy source (in this embodiment, a torsion spring controlled by release 110 mated to bearing block 106) and leveraging the moment of force applied to the deployable element 102 at the radius of sheave minor opening 804b, the deployable element 102 is guided from circumferential to linear motion with minimal frictional resistance, and is forced at the distal sharp end of the deployable element 102 into the skin tissue layer (in this application, a subcutaneous sensor, although alternatives as described herein or hereafter may be used). Such circumferential wrapping and initial retraction allows for a mechanism with a relatively small spatial volume (e.g., less than about 0.25 inches by 0.25 inches by 0.375 inches (about 6.35 mm by 6.35 mm by 9.53 mm)).

[0039] The conduit deployment assembly 100 allows sensors or other elements to be deployed to a depth in the subcutaneous tissue below the outer surface of the skin (e.g., to a depth of approximately 4-7 mm). The penetration depth can be controlled by the shape of a stop plate 112 attached to the sheave. As shown in FIGS. 1B, 1C, 7A, and 7B, the stop plate 112 includes a protrusion 116 that fits into a groove 118 in the cowling 104 and further includes an opening through which the stop plate 112 can be attached to the sheave. As the sheave rotates, the stop plate 112 rotates and moves the protrusion 116 within the groove 118 until it contacts a stop point at the end of the groove 118, thereby preventing further rotation of the sheave (and thus stopping the linear motion of the deployable element 102).

[0040] If the deployable element 102 is a sensor, the sensor can relay a signal back to the integrated front-end electronics 124 onboard the conduit deployment assembly 100. The integrated front-end electronics 124 can include a processor, which may be a relatively low-power processor compared to the processor onboard the larger body-worn device of which the conduit deployment assembly 100 is a part or to which it is attached. Some limited front-end processing may be performed on the sensor signal by the integrated front-end electronics 124. The resulting data may be transmitted via the service portion 120 to the processor on the body-worn device.

[0041] 1A and 1B, the release portion 110 is secured within the bearing block 106 until it is pulled away from the stop plate 112. FIG. 1C shows an alternative configuration in which the release portion 110 is secured within a cowling support 122 formed within the cowling 104. The cowling support 122 may simply be a raised loop formed from the material of the cowling 104, or it may be a separate element attached to the cowling 104.

[0042] 1D-1F illustrate an optional damper 130 suitable for use with the exemplary embodiments. For example, the damper 130 may be a viscoelectric damper attached to the cowling 104 and filled with a viscous medium to absorb energy from the conduit deployment assembly 100. The damper 130 includes one or more ridges 132 or feather-like elements around which the deployable element 102 may wrap, the ridges 132 being sized and shaped to slow the movement of the spring that deploys the deployable element 102. In some embodiments, the ridges 132 may be configured to affect only a portion of the stroke of the deployable element 102 (e.g., the last half to last quarter of the stroke).

[0043] FIG. 1F also illustrates an exemplary structure of the deployable element 102. As shown, an outer tubular structure (e.g., a thin-walled extruded polymer) can surround an inner core containing the sensor element. The tubular structure may be completely straight or may have a flared (or other shaped) end geometry for integration. This tubular structure may provide additional protection for the outermost coating of the deployable element 102 as sheave rotation drives linear (downward) movement of the sensor relative to stationary housing and cowling components. This tubular sleeve may remain stationary as the sensor advances through the inner diameter of the tube. Therefore, a low-friction polymer may be an appropriate material choice.

[0044] Additionally, optionally, a low radial force / compression seal may be provided at the interface between the housing enclosure and the exit location (i.e., opening 114) of the deployable element 102 where it contacts the body. This seal may be a low durometer silicone polymer (or a compatible elastomer) that may be insert molded into the housing base, or it may be a small O-ring shape or a more advanced "duck-billed" or "cone-funnel" type shape. Such a seal may prevent the ingress of liquids at that interface.

[0045] 2, 3, and 4A-4D illustrate the deployment of the deployable element 102. In the initial state (FIGS. 2 and 4C), the deployable element 102 is undeployed and is pulled back through opening 114 (shown, for example, in FIG. 17). As the sheave assembly 1000 rotates, it drives the deployable element 102 in a linear motion (downward in FIGS. 2, 3, and 4A) until the deployable element 102 reaches its full deployment range (FIGS. 3 and 4A).

[0046] 2, 3, 4A, 4B, and 4D further show an optional fluid conduit 202, which may be used when the deployable element 102 embodies a cannula, conduit, or needle for delivering a medication (e.g., liquid insulin). The fluid conduit 202 connects to the deployable element 102 (e.g., through a flexible, resilient, tapered, or extendable portion that allows the interface between the deployable element 102 and the fluid conduit 202 to move as the sheaves rotate, or by moving the length of the fluid conduit 202 in / out of an attached reservoir). The fluid conduit 202 can connect to a reservoir and deliver fluid from the reservoir through the deployable element 102. The fluid conduit 202 can form a bend when the deployable element 102 is in its undeployed or initial state (FIGS. 2 and 4C), and this bend can have the necessary play to allow the deployable element 102 to deploy without interrupting fluid communication from the reservoir to the fluid conduit 202 and to the deployable element 102. The deployable element 102 can have a sharp distal end, an open lumen at its distal end in fluid communication with the fluid conduit 202, and / or one or more holes (e.g., as shown in FIG. 4C) proximate its distal end for delivery of a medication such as insulin.

[0047] By using a rotational motion to drive the deployable element 102, the conduit deployment assembly 100 can be kept at such a compact size that it can be deployed by itself (FIG. 5) or together with other components of a drug delivery device (e.g., an automated insulin delivery, or "AID," device, see FIG. 6) in a fairly small housing.

[0048] 5, the conduit deployment assembly 100 fits within its own conduit assembly housing 502. In this form factor, the conduit deployment assembly 100 can be used, for example, to deploy a standalone sensor (e.g., a glucose sensor for a continuous glucose monitor).

[0049] In the combined example of Figure 6, the conduit deployment assembly 100 is housed within a larger integrated device housing 602 that can also house other components of a drug delivery device. For example, the conduit deployment assembly 100 can be used to deploy a glucose sensor or ketone sensor (as in Figure 5) used to control the delivery of a metered dose of insulin from an AID device. The AID device may also be housed within the integrated device housing 602. Separately or together with a glucose monitor, the AID device can also utilize the conduit deployment assembly 100 to deploy a needle, cannula, or conduit for delivering insulin or other medication.

[0050] 7A-7B show exploded views of the various components of the conduit deployment assembly 100 from different perspectives.

[0051] As previously mentioned, the conduit deployment assembly 100 rests on a base 108 that is shaped to hold the sheave assembly 1000. In particular, the base 108 comprises a semicircular stationary portion configured to support the sheave assembly 1000.

[0052] The sheave assembly 1000 can be controlled by a release portion 110, which includes a curved portion that fits within the bearing block 106. The bearing block 106 connects to a first bearing plate 702 that is fixed to a first end of the cowling 104, thereby holding the bearing block 106 in place. The release portion 110 captures a protrusion 116 of a stop plate 112. When the release portion 110 is pulled (see FIG. 1A), the curved portion is pulled out of the bearing block 106 and adjacent to the protrusion 116, thereby releasing the protrusion 116 (and thus the stop plate 112) from being captured by the release portion 110.

[0053] The release portion 110 (in this and the second embodiment) may be actuated by a shape memory alloy (SMA) wire that changes length in response to an external stimulus (e.g., the application of an electric current or a change in temperature). The SMA wire may be actuated, for example, by circuitry responsive to a transmitter / receiver within the conduit deployment assembly 100 indicating that it is time to deploy the deployable element 102 (as may be the case when the conduit deployment assembly 100 is part of a drug delivery device controlled by a signal from, for example, a cell phone or similar device), or may be activated by pressing a button, etc. Alternatively, the user may manually trigger the release portion 110 by pressing a button on the exterior surface of the integrated device housing 602 (e.g., the housing of an insulin pump) or by pulling on a prong or the release portion 110 itself, which may be on the exterior surface of the integrated device housing 602 and accessible to the user. In this latter example, the release portion 110 may be completely removed by the user while triggering the insertion of the deployable element 102 and may be discarded by the user. In an alternative embodiment, the release portion 110 may be connected to a gear mechanism and / or plunger element in a reservoir of a drug delivery device that is driven by the gear mechanism. As the gear mechanism advances, it may reach a threshold point at which the release portion 110 is pulled or pushed, causing deployment of the deployable element 102.

[0054] Stop plate 112 is secured to sheave 706 (see Figures 10A and 10B for details) which receives energy from spring 704 (in this example, a torsion or coil spring). When stop plate 112 is released, sheave 706 rotates under the action of spring 704, causing protrusion 116 to rotate inside a groove in cowling 104. When protrusion 116 reaches the end of the groove, stop plate 112 is arrested and stops moving.

[0055] A deployable element support 712 is also attached to sheave 706. The deployable element support 712 contains a deployable element 102 (in this case, a sensor in the form of a laminated wire) that is wrapped circumferentially around sheave 706 and, optionally, inserted into ridges in the deployable element support 712, as shown in FIG. 11. The deployable element 102 is further constrained by cowling 104 to rotate within a fairly small passageway within conduit deployment assembly 100. For example, when deploying a sensor in the form of a wire having a diameter of 0.0004 inches (approximately 0.01 mm), the passageway may be approximately 0.004 inches (approximately 0.1 mm) wide.

[0056] 1B, the structure of cowling 104 and base 108 controls the shape of this passageway. The passageway is configured so that rotational motion of deployable element 102 is converted to linear motion near openings in base 108. The openings are positioned to receive the ends of deployable element 102 as it moves linearly toward the user's skin.

[0057] The sheave 706 is attached to the second end of the cowling 104 through a second bearing plate 710. The sheave 706 can be properly positioned relative to the bearing plate 710 using a spacer 708.

[0058] The conduit deployment assembly 100 may be attached to a support 714, which may form part of the housing or may serve as a cradle or tray for a drug delivery device (e.g., an integrated device housing 602) or a glucose sensing device.

[0059] FIG. 8 shows the deployable element support 712 in more detail.

[0060] The deployable element supports 712 provide support to the deployable elements 102 , connect the deployable elements 102 to the sheaves 706 , and properly position the deployable elements 102 around the periphery of the sheaves 706 .

[0061] Deployable element support 712 includes a body portion 802 that is circular in shape (to correspond to the shape and general size of sheave 706) and includes sheave main openings 806 that are sized and shaped to receive the main support posts extending from the sheaves. For additional support and to properly orient deployable element support 712, body portion 802 also includes sheave sub-openings 804a, 804b, and 804c. These sub-openings correspond to the sub-supports of sheave 706.

[0062] The deployable element support 712 may also include circuitry 808, such as embedded electronic hardware, used to collect data from sensors or to control the flow of liquid medication to the cannula. In some embodiments, the deployable element 102 may include conductive traces that connect sensors (for example) through the deployable element 102 to the deployable element support 712 and associated circuitry 808.

[0063] In one example, the deployable element support 712, the service portion 120, and / or the deployable element 102 may be formed from a multi-layer circuit board, such as a printed circuit board (PCB). An example of the configuration of the different layers of a circuit board is shown in Table 1 below.

[0064] [Table 1]

[0065] 9 shows an alternative embodiment of a deployable element support 712. In addition to the elements described above, the deployable element support 712 of FIG.

[0066] 10A and 10B show the sheave assembly 1000 in more detail.

[0067] In sheave assembly 1000, sheave 706 connects to deployable element support 712 through a set of sheave supports that pass through corresponding openings in deployable element support 712. Sheave main forward support 1004 passes through sheave main opening 806 in deployable element support 712, while sheave secondary forward supports 1002a, 1002b, 1002c pass through sheave secondary openings 804a, 804b, 804c. Sheave main forward support 1004 then passes through spacer 708 and is received in corresponding openings in bearing plate 710, which supports sheave 706.

[0068] On the opposite side, a similarly positioned secondary support passes through a corresponding opening in stop plate 112. Sheave main aft support 1008 is surrounded by spring 704, which includes a bent end that communicates with an opening in stop plate 112 and with sheave 706, allowing energy to be applied to sheave 706. Sheave main aft support 1008 then passes into a corresponding opening in bearing plate 702, which supports sheave 706.

[0069] Figure 11 is a perspective view showing the electrical connections between sensors stored in (or forming) the deployable element 102 and the integrated front-end electronics 124 and the electrical service portion 120 for connecting the integrated front-end electronics 124 to the back-end electronics in the main body of the drug delivery device.

[0070] The sensors in the deployable element 102 can be electrically connected to the deployable element support 712 and can transmit electrical sensor signals to one or more contact points 1104 a, 1104 b on the deployable element support 712. One or more conductive contacts 1102 a, 1102 b can be attached to the contact points 1104 a, 1104 b, respectively, to transmit the signals to the integrated front-end electronics 124. After initial processing, the integrated front-end electronics 124 can transmit the processed data to the main processor of the body-worn device via circuitry in the service portion 120. The service portion 120 can connect to circuitry on the body-worn device for the purpose of transferring the processed data (and / or, optionally, the raw sensor signals).

[0071] This configuration allows for initial processing of data as close to the sensor as possible, improving computation time and reducing the workload on the main processor (back-end electronics) of the body-worn device.

[0072] The above-described embodiments utilize a release 110 that can be pulled to release a protrusion 116 on the stop plate 112, which allows the sheave 706 to rotate under spring action. In these embodiments, the release 110 acts to hold the stop plate 112 in place until it is actuated. Figures 12A-12D show an alternative release mechanism suitable for use with the exemplary embodiments, which can be useful when space is limited.

[0073] In this release mechanism, the protrusion 116 on the stop plate 112 is held in place by two pins attached to the base 108. The first pin 1202 is L-shaped and is attached to a first pin pivot 1206. The first pin 1202 can be configured to hold the protrusion 116 in place until it pivots on the first pin pivot 1206, moving the first pin 1202 out of the way of the protrusion 116.

[0074] To that end, the second pin 1204 is C-shaped and is attached at one end to a second pin pivot 1208. At the other end, the second pin 1204 is attached to a release trigger 1210, such as an SMA wire.

[0075] Before the trigger 1210 is actuated, the release mechanism is in the configuration shown in Figures 12A and 12C. In this configuration, the protrusion 116 pushes against the first pin 1202 (indicated by the down arrow in Figure 12C). The force exerted by the protrusion 116 would cause the first pin 1202 to rotate on the first pin pivot 1206 unless the first pin 1202 is prevented from rotating by the second pin 1204.

[0076] When trigger 1210 is actuated (e.g., by manually pulling trigger 1210 or by applying a current to trigger 1210 when trigger 1210 is embodied as an SMA wire), this causes second pin 1204 to rotate about second pin pivot 1208 (FIG. 12D) and releases first pin 1202. First pin 1202 is now free to rotate about first pin pivot 1206, thus moving first pin 1202 away from protrusion 116. With first pin 1202 unobstructed, sheave 706 is free to rotate under the action of spring 704.

[0077] (Linear deployment mechanism with optional introducer) Alternatives to the first embodiment utilize linear motion rather than rotational motion. Examples of these embodiments are shown in Figures 13-16.

[0078] In this embodiment, the deployable element 102 is not constrained by the cowling and base and may therefore be more prone to buckling than in the first embodiment. Therefore, an introducer 1318 is optionally provided to stiffen the deployable element 102. The introducer 1318 may be positioned parallel to the deployable element 102 so that the introducer 1318 supports the deployable element 102 during deployment.

[0079] However, it may be undesirable to leave the introducer 1318 embedded in the user's skin for the length of time that the deployable element 102 is being deployed, as this increases the size of the entry point into the user's skin and can cause discomfort (among other disadvantages). Therefore, the exemplary embodiment provides a design that allows the introducer 1318 to automatically retract after it has served its purpose of assisting in the deployment of the deployable element 102.

[0080] FIG. 13 is an exploded view showing the various parts of a straight conduit deployment assembly 1300.

[0081] An anti-rotation pin 1302 connects the harness 1304 to a housing that holds the conduit deployment assembly 1300. The anti-rotation pin 1302 prevents the harness 1304 from rotating (e.g., due to the force applied by the deployment spring 1306). The harness 1304 may be connected at the base of its legs to a base 1326. The base may be sized and shaped to be complementary to an opening in the base 1326 that forms the bottom of the housing in which the conduit deployment assembly 1300 is stored.

[0082] The harness 1304 may be configured to support other elements of the conduit deployment assembly 1300 , including the deployment spring 1306 , the bearing cup 1308 , the deployable element 102 , the buffer plate 1312 , and the suspension 1314 .

[0083] The deployment spring 1306 (e.g., a helical compression spring) stores and releases energy that allows the deployable element 102 to be driven linearly into the user's skin. The deployment spring 1306 presses against a bearing cup 1308, which is sized and shaped to press against the deployable element 102, thereby transferring energy from the deployment spring 1306 to the deployable element 102. The bearing cup 1308 is restrained by a release portion 1310, which prevents the deployment spring 1306 from deploying the deployable element 102 until the release portion 1310 is moved. The bearing cup 1308 can include a protrusion that allows the introducer 1318 to be retracted, as described in more detail below in connection with FIG. 15 .

[0084] The buffer plate 1312 fits in or over a complementarily shaped opening in the suspension 1314 to support the deployable element 102. The opening in the suspension 1314 has an opening with a first, relatively narrow side and a second, relatively wider side. The narrower side allows the deployable element 102 and introducer 1318 to be deployed. The introducer 1318 is then pushed toward the second, relatively wider side of the suspension 1314 due to the shape of the kick spring 1324, thereby retracting under the action of the retraction spring 1316 (see discussion associated with FIGS. 14 and 15 ).

[0085] The sacrificial sleeve 1320 temporarily holds the introducer 1318 and the deployable element 102 together, allowing them to be moved as a unit. For a more detailed description of the sacrificial sleeve 1320, see FIG.

[0086] The kick spring 1324 and support tube 1322 may be attached directly to the base 1326. The remaining elements of the conduit deployment assembly 1300 may be attached to the harness 1304, which is then secured to the base at the bottom of the legs of the harness 1304.

[0087] 14 , the deployment spring 1306 is initially held in a compressed state by the release portion 1310, causing it to store energy. When the release portion 1310 is removed, the energy stored in the deployment spring 1306 is released and transferred to the bearing cup 1308. The bearing cup 1308 can then force the deployable element 102, along with the introducer 1318, through an opening in the suspension portion 1314, coupling the introducer 1318 to the deployable element 102. This causes the combination of the deployable element 102 and the introducer 1318 to translate linearly a first predetermined distance. This action stretches the retraction spring 1316 attached to the introducer 1318, thereby storing energy in the retraction spring 1316.

[0088] After a first predetermined distance, both the deployable element 102 and the introducer 1318 move through an opening in the kick spring 1324. The pointed end of the introducer 1318 creates an opening in the user's skin through which the deployable element 102 can pass.

[0089] The opening in the kick spring 1324 and the introducer 1318 are complementary shaped so that as the introducer 1318 moves downward through the opening in the kick spring 1324, it is pushed toward the side of the kick spring 1324 (see FIG. 15 ). The introducer 1318 includes a geometric portion having an angled structure 1402 that is wider than a first portion of the opening in the suspension portion 1314 through which the introducer 1318 first passes. A second portion of the opening in the suspension portion 1314 is oriented toward the side of the suspension portion 1314 in the same direction that the kick spring 1324 pushes the introducer 1318, and has a larger opening that corresponds to the size and shape of the angled structure 1402.

[0090] As the angled structure 1402 moves toward the second portion of the opening due to the interaction of the kick spring 1324 with the introducer 1318, two things happen. First, the introducer 1318 moves toward the side of the bearing cup 1308, where a groove is cut into the bearing cup 1308. This releases the introducer 1318 from the action of the deployment spring 1306. Second, the retraction spring 1316, which was previously prevented from retracting the introducer 1318 by the suspension 1314, is now free to pull the introducer 1318 back onto the suspension 1314. This causes the introducer 1318 to retract inside the base 1326, which provides the introducer 1318 with a safety housing that prevents the sharp end of the introducer 1318 from contacting the user's skin again.

[0091] As described above, the introducer 1318 and the deployable element 102 can be coupled so that they move linearly together. Figure 16 shows an example of a sacrificial sleeve 1320 configured to temporarily couple these two elements. The sacrificial sleeve 1320 temporarily increases the structural rigidity of the elements during their combined translation in one desired direction, but then slices, peels, crumples, or otherwise separates from the elements once the desired translation amount or position is reached. This allows the separate elongate elements to be disconnected and move differently relative to each other in the same or opposite directions.

[0092] For example, the sacrificial sleeve 1320 can be a thin-walled element formed from a polymeric material. As the suspension 1314 lowers under the action of the deployment spring 1306, the sacrificial sleeve 1320 can be compressed against the kick spring 1324. At this point, it can be crimped, cut, or separated along a predetermined separation line. The sacrificial sleeve 1320 can remain within the conduit deployment assembly 1300, for example, by being captured within a support tube 1322.

[0093] Similar to the above embodiments, the deployable element 102 may be a cannula or needle for delivering a medication such as insulin, a glucose or ketone sensor (e.g., an electrochemical sensor, a fiber optic sensor, a wire sensor, an optofluorescence sensor, etc.), a temperature sensor, or an activity sensor.

[0094] (Structure for epidermal tension) Because the above embodiments may be used with particularly thin and flexible elements, these elements may be particularly susceptible to buckling or deflection. Any of these embodiments may benefit from deploying the cannula or sensor (or deployable element 102) into pre-tensioned tissue to reduce the likelihood of buckling. Figures 17-20 show exemplary structures that allow the user's tissue (e.g., epidermal tissue) to be tensioned before the cannula / sensor is deployed.

[0095] 17 and 19 show one example of a tensioning structure that may be present on the base 108 of the conduit deployment assembly 100. The tensioning structure includes an annular ring 1702 that is centered about an opening in the base of the conduit deployment assembly 100 or conduit deployment assembly 1300 (through which the deployable element 102 passes). The annular ring 1702 may be any suitable size, and in the example shown, the outer diameter of the annular ring 1702 is approximately 0.25 inches (approximately 6.35 mm).

[0096] The annular ring 1702 creates a gap 1706 in the center of the annular ring 1702. When the base of the conduit deployment assembly is pressed into the user's skin 1704, the skin bulges slightly into the gap 1706, which causes the skin 1704 to become taut.

[0097] The example in Figure 17 shows an annular ring having a semicircular cross section, although this is not required and other shapes may be suitable depending on the application. For example, Figure 20 shows annular ring cross sections having different shapes: a triangular cross section 2002, a trapezoidal cross section 2004, an oval cross section 2006, and a rectangular cross section 2008.

[0098] Figure 18 shows an alternative configuration for the tensioning element. In this case, the tensioning element collapses the skin 1704 inward rather than expanding the skin 1704 outward as in Figure 17. To accomplish this, the bottom surface of the base 108 may be protruded outward with a convex protrusion 1802, which may be centered on the opening 114. This pushes the skin 1704 away from the base 108, thereby pulling the skin taut against the base 108. When the deployable element 102 is deployed at an angle, the opening 114 may be positioned so that the deployable element 102 and the tensioned skin surface into which the deployable element 102 is to be inserted are closer to perpendicular to each other, or more perpendicular than if the opening were centered on the protrusion 1802.

[0099] Exemplary Cannula and Sensor Configurations Additionally, the cannula or sensor itself may be structured or configured to support deployment, as shown in the exemplary deployable element 102 of Figures 21A-23.

[0100] For example, Figures 21A-22 show exemplary sensors made from layered compositions of polymers, metals, and other materials. These materials can be combined to form various cross sections and employed to develop desired directional stiffness (generally, but not necessarily, axial stiffness). This can improve deployment and penetration of thin, flexible, elongated elements into human skin over periods of implanted use that can last up to multiple days. Additionally, it can maintain conductive signal conduits / traces to embedded electronic hardware.

[0101] 21A shows, at the top, two different deployable elements 102, one on the left corresponding to a deployable element from a first, rotational embodiment, while one on the right corresponds to a deployable element from a second, linear embodiment. The close-up view at the bottom of the page depicts one configuration that may be suitable for use with either of these embodiments.

[0102] The deployable element 102 can be composed of a core layer 2102 , an outer layer 2104 , a first conductor / electrode 2106 , a second conductor / electrode 2108 , and / or a support 2110 .

[0103] The core layer 2102 can be formed from a material (e.g., stainless steel, titanium, or another metal) that is sufficiently rigid or has a high enough modulus of elasticity to prevent buckling or deflection of the deployable element 102. The support 2110 can further improve the directional stiffness of the deployable element 102 to improve deployment penetration and can be made from materials similar to the core layer 2102 and / or polymer, such as polyimide, FEP, PTFE, PP, PCL, PGA, PGLA, PLA, silicone, etc. The support 2110 can additionally or alternatively be a biospecific coating.

[0104] The outer layer 2104 may be a coating such as an enzyme or other bionic compound that protects the other layers while protecting the point of entry into the user's skin, and it may also be electrically insulating, thereby preserving the electrical signal traveling along the conductors / electrodes 2106, 2108.

[0105] The first and second conductors / electrodes 2106, 2108 can form traces that carry electrical signals from the distal end of the deployable element 102 to embedded circuitry used to process the signals. The conductors / electrodes 2106, 2108 can be made of a conductive material, such as, for example, a copper alloy, nickel, silver, gold, etc. The conductors / electrodes 2106, 2108 can extend along the entire length of the deployable element 102.

[0106] Once assembled, the multi-layer construct may be modified at the distal tip to support penetration into the user's skin, for example, by ablating material at the distal end, thereby removing all material except for the core layer 2102 and sharpening the core layer 2102.

[0107] 21B and 21C show additional examples of deployable elements in the form of thin, flexible, multi-layered laminated wires. In these embodiments, different layers 2114a, 2114b, 2114c, 2114d, 2114e... may be coated sequentially onto a core 2116. For example, the core 2116 may be a length of wire (e.g., 0.005 inch (approximately 0.13 mm) in diameter) made of tungsten or stainless steel. The layers 2114a... may be insulators, conductors, enzymes, etc. coated down the length of the wire. The final layer may be a protective biocompatible coating 2112.

[0108] In some embodiments (e.g., as shown in Figure 21B), different layers may be scraped away so that each is exposed in turn. Alternatively (see Figure 21C), various layers may be scraped away in specific areas along the length of the wire, selectively exposing them.

[0109] 23 shows an exemplary configuration suitable for the conduit. The conduit may include a reinforced tip 2304 at its distal end configured to penetrate the skin of a user. The tip 2304 may be pointed or sharp to facilitate penetration.

[0110] The conduit may be hollow to allow a liquid medication to be administered through the conduit. To that end, one or more ports 2302 may be present at the distal end of the conduit near the tip 2304. The ports 2302 may also be on the side of the conduit to allow for administration of the liquid medication.

[0111] The conduit may have a substantially rectangular cross section 2306, as in the illustrated example. This cross section 2306 provides strength to the conduit and prevents it from collapsing, which would prevent it from delivering a liquid medication. Other suitable shapes may be used if desired. The proximal end of the conduit may include an interface that allows the conduit to be connected to a fluid conduit 202 that connects to a reservoir for delivering a liquid medication.

[0112] The rotary deployment mechanisms shown in Figures 1A-12D are described above as "introducer-less." Such systems can deploy elongate or deployable elements to depths of (e.g.) 2-10 millimeters, measured perpendicularly from the outer skin surface or, alternatively, linearly along the length of the deployable element; such "introducer-less" nature helps minimize trauma during penetration and minimize wound size. Minimizing these factors is known to improve the effectiveness of the elongate elements' function within tissue (typically deep subcutaneously).

[0113] The embodiment shown in Figures 24A-32B includes an introducer that minimally penetrates the toughest and strongest outermost layers of skin (from the stratum corneum to the dermis), reaching a depth of only 1-3 millimeters, and then can be retracted from the skin while or after the deployable element 102 (see, e.g., Figures 32A-32B) penetrates further down into the subcutaneous tissue. Thus, the accompanying deployable element only needs to independently slide into the softer subcutaneous layers or the least tough layers of skin (mostly fat and connective tissue) and remain there for the duration of use. Of course, an assist system could be configured to drive an auxiliary sharp element along with the deployable element to the full depth, but reduced penetration may still be desirable to minimize trauma and wound size.

[0114] These embodiments are particularly useful when applied in connection with elongate or deployable elements that are of very small size or diameter, have geometries, or are made from particular materials whose inherent stiffness (e.g., Young's modulus) is too weak to independently deliver through the skin into the tissue medium without buckling.

[0115] Subsequent figures contain many of the same features previously highlighted in Figures 1A-12D and therefore will not be redundantly described. Figure 24A shows an exemplary rotatable cannula deployment mechanism utilizing an introducer to penetrate the outermost layer of skin, while Figure 24B shows the rotatable cannula deployment mechanism of Figure 24A with an exemplary cowling 704.

[0116] Cowling 704 includes integral passageways, including in this embodiment a first passageway 2406 and a second passageway 2408. These passageways are configured to accommodate, align with, and guide an introducer (e.g., as shown in FIGS. 25A-26C) that serves as the primary tissue-piercing element.

[0117] The deployment mechanism also includes, inside the cowling, a retention block 2402 and an introducer spring 2404. The design and function of these elements are described in connection with Figures 28A-28D and 30A-31.

[0118] 25A and 25B show an exemplary introducer 2502 suitable for use with the described embodiments. The introducer 2502 may include a tapered, pointed end 2504 with a sharp edge 2506.

[0119] The introducer 2502 further includes a flexible section 2508 that provides a spring-like section that allows it to flex longitudinally without yielding. When the introducer is in the pre-deployment configuration, the flexible section 2508 is curved around the cowling 104 and is driven by the above-described rotational movement of the sheave 706. When the introducer is deployed, the flexible section 2508 straightens, driving the pointed end 2504 into the skin.

[0120] Interface features 2510, such as protrusions, recesses, flanges, or hooks, allow the introducer 2502 to be connected to the introducer spring 2404, as shown in more detail in Figures 31A-31B.

[0121] The alignment feature 2512 may be a bend or curve that allows the portion of the introducer 2502 closest to the pointed end 2504, referred to herein as the introducer guide 2514, to be positioned adjacent to or flush with the deployable element 102. Thus, the introducer can penetrate the outermost layer of skin and guide the deployable element 102 into the body.

[0122] 26A-26C, it is envisioned that several embodiments of the introducer 2502 may include a variety of shapes and termination conditions 2516, 2518 that are specifically configured for particular applications. A few variations are shown here by way of example, but these are by no means inclusive of the many possible options.

[0123] 27A-C illustrate how an exemplary introducer 2502 can be positioned relative to the first and second passageways 2406, 2408 of the cowling 104 and the sheave 706. The interface feature 2510 of the introducer 2502 is configured to rest within a corresponding groove 2702 in the sheave 706. When assembled, the interface feature 2510 extends through the first passageway 2406 of the cowling 104, while the flexible portion 2508 extends around and outside the cowling 104. The alignment element 2512 allows the introducer 2502 to bend back toward the deployable element 102 and through the second passageway 2408 of the cowling 104.

[0124] During assembly, the flexible portion 2508 of the introducer 2502 flexes to match the geometry of the sheave 706 and the interface features 2510 are seated within the grooves 2702 on the sheave 706 .

[0125] The main length of the introducer 2502 (corresponding to the flexible portion 2508) lies against the outermost surface of the cowling 104, while a shorter length (corresponding to the introducer guide 2514) fits within a second passage 2408 integrated into the cowling 104.

[0126] This configuration includes several other components, which may be separate pieces that are combined by assembly. Alternatively or additionally, several elements may be integrated into a single, combined part. Figures 28A-28D show these additional components.

[0127] During assembly, with the introducer 2502 in its required position, the retaining block 2402 is added and secured using the cowling 104 and sheave 706. The retaining block 2402 may be, for example, an injection molded part made from a polymeric material selected for low friction to reduce mechanical energy loss during the relative sliding functional motion of the introducer 2502. The retaining block 2402, along with any attached (or integrated) components, is secured directly to the cowling 104 or other static element of the system by a snap fit, press fit, crimping, or other suitable attachment method.

[0128] The retention block 2402 may include a recess 2802 constructed and arranged to position, restrain, and retain an escapement clip 2804 or similar element that provides low-force deflection and serves to set the position of the introducer spring 2402 and latching element within the system. The introducer spring 2402 can exert sufficient force to retract the introducer 2502 during function of the system. An exemplary introducer spring 2402 is shown in more detail in FIGS. 31A-31B.

[0129] The escape clip 2804 may be constructed from a stamped and formed thin metal section. Such an escape clip 2804 may be part of the cowling 104 or may be fixed to the cowling 104. Also included in this configuration is a retaining flexure 2806. The primary function of the retaining flexure 2806 is to provide a light normal force applied (e.g., directly) to the outward-facing surface of the introducer 2502, directed radially inward toward the center of the cowling 104. This retaining flexure 2806 also establishes an initial escape position that allows the introducer 2502 to snap and deflect from its temporarily held curved shape back to its original straight beam shape. The retaining flexure 2806 in this embodiment is constructed from stamped and formed thin metal, with attachment features and a deflecting cantilever beam-shaped segment in its geometry. This element may also be attached directly to the cowling 104.

[0130] Figures 29A-C show an exemplary sequence of introducer 2502 positions during deployment and prior to retraction. Figure 29A shows the initial position of introducer 2502 at the beginning of rotational movement of the contacting sheave 706. Figure 29B shows the position where introducer 2502 is released from the restraining force of retaining flexure 2806 and rotation of sheave 706. Figure 29C shows the moment when introducer 2502 has elastically returned to its straight shape as manufactured and is just prior to its retraction by introducer spring 2404.

[0131] While in its fully penetrated (deployed) position, the introducer 2502 is engaged through interface features 2510 with a geometry integrated into or assembled into the introducer spring 2404. Figure 30B, showing the introducer 2502 in the fully penetrated position, illustrates the point where the introducer spring 2404, while now coupled to the introducer 2502, has been released from its static holding position under the escape clip 2804, thus allowing the introducer 2502 to be retracted from the penetrated tissue.

[0132] 30A, showing the introducer 2502 in a pre-deployment state, illustrates that the load on the introducer spring 2404 (in this embodiment, a constant force type) is held by the escapement clip 2804 and is therefore isolated (or decoupled) from the main driving energy source during the driving of the main degree of rotational motion. The system configuration helps to reduce the force capacity required of the introducer spring 2404 so that it is only slightly greater than the frictional forces on the introducer 2502 due to contact with tissue and the surfaces of the cowling 104 and retention block 2402. Therefore, this spring force will also minimally interfere with the main force and inertia of the rotational motion of the sheave 706.

[0133] FIG. 31 represents exemplary interface features of the introducer 2502 and interface spring 2404. These features allow these elements to connect for retraction of the introducer 2502 during the system's rotational motion cycle. The introducer interface feature 2510 is discussed above. Meanwhile, the spring interface 3102 has corresponding geometric shapes, such as a hook for connecting to the hooked end of the introducer interface feature 2510 and a central hole through which the introducer 2502 passes. In some embodiments, the end of the introducer spring 2404 can be easily formed into a subtle "U" or hook shape that will latch onto the flattened edge shape of the introducer interface feature 2510. This embodiment represents the most basic configuration for functionality. However, alternative features that provide interface functionality by varying the nuances of the components and interface geometry and materials will be readily apparent to those skilled in the art.

[0134] The opposite end of the introducer spring 2404 may be shaped into a coil 3104, which can serve to reduce the overall size of the system.

[0135] 32A-B correspond to FIGS. 30A and 30B, respectively, and show an exemplary "pre-deployment state" compared to the state when the introducer 2502 and deployable element 102 are in the "fully inserted" position.

[0136] These figures illustrate that in an alternative embodiment, the tip positions of the introducer 2502 and the deployable element 102 are held at approximately the same distal location prior to deployment, but the introducer can extend distally beyond the deployable element 102. Upon a deployment triggering event, the introducer 2502 and the deployable element 102 move in close proximity to one another with the same travel or penetration amount. Upon reaching its escape position during rotational movement, the introducer 2502 reaches its maximum penetration depth (D i ), which may be 1-3 millimeters below the outermost surface of the skin, as suggested above. At this point in the rotation, the introducer 2502 is pulled by the introducer spring 2404, retracted, and moved in the reverse direction back inside the enclosure of the deployment device, where the tip of the introducer 2502 comes to a rest and retracts into its initial position.

[0137] Meanwhile, the rotational movement of sheave 706 continues along its forward direction, and deployable element 102 (which in this embodiment is directly fixed to sheave 706 at the end of deployable element 102 opposite its tip) moves its tip to a final depth (D ) of 2 to 10 millimeters, or more preferably 4 to 6 millimeters, measured, for example, perpendicular to the outer skin surface or alternatively measured linearly along the length of deployable element 102 (e.g., if the angle of penetration is designed not perpendicular to the skin surface). s ) Once the rotational movement reaches its stop position, the deployable element 102 remains within the tissue for the duration of its use.

[0138] The figure also shows a fixed point 3202 (in this embodiment, shaft-shaped, although other configurations are possible) that holds the coiled portion 3104 of the introducer spring 2404, allowing it to unwind and then retract. Other appropriately configured elastic, spring-like elements can be used to provide a similar function. The angle of insertion can also be adjusted, e.g., to 30-60 degrees from vertical.

[0139] Having an introducer element that does not penetrate as deeply into tissue as the deployable element 102 (e.g., an infusion cannula or sensor element, as described above) achieves many objectives. The introducer element can penetrate a tougher layer of skin (e.g., the stratum corneum) to create a more flexible hole or introduction path for the deployable element 102, which can then be retracted into the delivery device (e.g., into a drug delivery device or continuous glucose meter housing). This causes less pain to the user and less trauma to the site where penetration occurs. Therefore, with this design and approach, less “wound healing” must occur. For sensors such as continuous glucose sensors, for example, this reduced wound healing allows the sensor to “warm up” more quickly and provide a reading more quickly or provide a more accurate reading than would be the case in other cases where the introducer or needle element penetrates to a depth greater than or approximately equal to the depth penetrated by the sensor (or deployable element). Also, for example, less trauma is beneficial when a cannula is the deployable element 102 and a drug, such as insulin or GLP-1 or a similar drug, is being infused into the patient through the cannula. The reduced trauma and reduced wound healing can also reduce the likelihood of blockage at or near the distal end of the cannula. Thus, having an introducer (that does not remain below the skin surface) that does not penetrate as far as a deployable element (that remains below the skin surface) is highly beneficial to both the patient and the function of the medical device (e.g., either a drug infusion device or a continuous glucose monitor (CGM)).

[0140] Those skilled in the art will understand that the above concepts can be applied as described above to a needle acting as an introducer and to an infusion cannula or analyte sensor acting as a deployable element. More specifically, the introducer can be in the form of a needle in some embodiments. The needle can be positioned inside the lumen of a hollow deployable element. In other embodiments, the needle can be hollow and the deployable element can be disposed inside the lumen of the needle. As described above, the needle can penetrate the outermost (toughest) layer of the skin and then retract out of the skin and into the medical device housing from which it was deployed, with the deployable element continuing to penetrate the softer layers of subcutaneous tissue below (either during the needle retraction or after the needle has penetrated distally but before the needle retracts distally). In this way, the needle does not penetrate distally farther than the deployable element, resulting in less pain for the user and less trauma at the insertion site.

[0141] It will be appreciated that the exemplary device shown in the above block diagram may represent one functionally descriptive example of many potential implementations. Thus, the division, omission, or inclusion of block functions shown in the accompanying figures does not infer that hardware components, circuits, software, and / or elements for implementing those functions will necessarily be divided, omitted, or included in the embodiment.

[0142] Some embodiments may be described using the phrase "in one embodiment" or "embodiment" and their derivatives. These terms mean that a particular feature, structure, or feature portion described in connection with an embodiment is included in at least one embodiment. The appearance of the phrase "in one embodiment" in various places throughout the specification does not necessarily all refer to the same embodiment. Furthermore, unless otherwise stated, it is recognized that the above features can be used together in any combination. Thus, any features discussed separately can be employed in combination with each other unless the features are noted as being incompatible with each other.

[0143] To generally refer to the notation and nomenclature used herein, the detailed descriptions herein may be presented in terms of program procedures executed on a computer or network of computers. These procedural descriptions and representations are used by those skilled in the art to most effectively convey the substance of their work to others skilled in the art.

[0144] Some embodiments may be described using the terms "coupled" and "connected," along with their derivatives. These terms are not necessarily intended as synonyms for each other. For example, some embodiments may be described using the terms "connected" and / or "coupled" to indicate that two or more elements are in direct physical or electrical contact with each other. However, the term "coupled" can also mean that two or more elements are not in direct contact with each other, but yet still cooperate or interact with each other.

[0145] It is emphasized that the Abstract of the present disclosure is provided to allow the reader to quickly ascertain the nature of the technical disclosure. It is understood that the Abstract is not used to interpret or limit the scope or meaning of the claims. Moreover, in the foregoing Detailed Description, it can be recognized that various features are grouped together in a single embodiment for the purpose of streamlining the disclosure. This method of disclosure is not to be interpreted as reflecting an intention that the claimed embodiments require more features than are expressly recited in the claim. Rather, as the following claims reflect, inventive subject matter lies in less than all features of a single disclosed embodiment. Accordingly, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment. In the appended claims, the terms "including" and "in which" are used as the plain-English equivalents of the terms "comprising" and "wherein," respectively. Furthermore, the terms "first," "second," "third," etc. are used merely as labels and are not intended to impose numerical requirements on their objects.

[0146] What has been described above includes examples of the disclosed architecture. Of course, it is not possible to describe every conceivable combination of components and / or methodologies, and one of ordinary skill in the art will recognize that many more combinations and permutations are possible. Accordingly, the novel architecture is intended to embrace all such alterations, modifications, and variations that fall within the spirit and scope of the appended claims.

[0147] Exemplary embodiments may include, but are not limited to, the following:

[0148] [Embodiment 1] 1. A device comprising: a deployable element configured to be deployed subcutaneously; an introducer configured to remain adjacent to the deployable element during deployment to support the deployable element during deployment; and a base having an opening such that the deployable element and the introducer are configured to extend through the opening, wherein the deployable element is configured to extend into a user's skin a first amount during deployment and the introducer is configured to penetrate and extend into the user's skin a second amount less than the first amount.

[0149] [Embodiment 2] 2. The device of embodiment 1, wherein the deployable element is configured to extend into the user's skin to a depth of 4 to 7 mm.

[0150] [Embodiment 3] The device of embodiment 1 or 2 above, wherein the introducer is configured to penetrate the outermost layer of the user's skin, including the stratum corneum through the dermis layer.

[0151] [Embodiment 4] The device of any one of embodiments 1-3 above, wherein the introducer is configured to extend into the user's skin to a depth of 1 to 3 mm.

[0152] [Embodiment 5] A device described in any one of the above embodiments 1-4, wherein the introducer is configured to automatically retract through the opening in the base after reaching a maximum deployment distance.

[0153] [Embodiment 6] A device described in any one of the above embodiments 1-5, wherein the deployable element is configured to continue extending even after the introducer has reached its maximum deployment distance.

[0154] [Embodiment 7] The device of any one of embodiments 1-6 above, wherein the deployable element is selected from the group consisting of a cannula, a conduit, a needle, or a sensor.

[0155] [Embodiment 8] The device of any one of embodiments 1-7 above, wherein the deployable element is a glucose sensor configured to perform continuous glucose monitoring or a ketone sensor.

[0156] [Embodiment 9] The device described in any one of the above embodiments 1-8, further comprising a rotation mechanism having an outer periphery, the deployable element being wrapped around at least a portion of the outer periphery, the rotation mechanism configured to rotate the deployable element around the outer periphery, and configured to selectively constrain the deployable element so that the rotation of the deployable element is converted into linear motion.

[0157] [Embodiment 10] The device of embodiment 9 above, further comprising an introducer spring coiled around a fixed point on the device.

[0158] [Embodiment 11] The device described in embodiment 10 above, further comprising: a cowling that houses at least a portion of the rotation mechanism; a retaining block configured to secure the introducer to the cowling; and one or more escape clips provided in corresponding recesses in the retaining block and configured to secure the introducer spring.

[0159] [Embodiment 12] An apparatus described in any one of the above embodiments 10-11, wherein the introducer spring has an introducer spring interface configured to engage with a corresponding interface of the introducer.

[0160] [Embodiment 13] An apparatus described in any one of the above embodiments 9-12, wherein the rotation mechanism is a sheave assembly.

[0161] [Embodiment 14] An apparatus described in any one of the above embodiments 9-13, wherein the apparatus further comprises a torsion spring configured to provide energy to rotate the rotation mechanism.

[0162] [Embodiment 15] A device described in any one of embodiments 9-14 above, wherein the device further comprises a stop plate configured to control the extent to which the deployable element extends beyond the opening.

[0163] [Embodiment 16] A device described in any one of embodiments 9-15 above, wherein the device further comprises a fluid conduit configured to connect the deployable element to a reservoir.

[0164] [Embodiment 17] The device described in any one of the above embodiments 1-8, further comprising a linear deployment mechanism configured to extend the deployable element and the introducer.

[0165] [Embodiment 18] A device described in any one of the above embodiments 1-17, wherein the device further comprises at least one convex or concave protrusion on the base, the protrusion being sized and shaped to tension the user's skin near the opening when the base is pressed against the skin.

[0166] [Embodiment 19] A device described in any one of embodiments 1-18 above, wherein the deployable element has a layered structure including at least one polymer, at least one metal, and a coating.

[0167] [Embodiment 20] A device described in any one of embodiments 1-19 above, wherein the deployable element is provided with one or more conductive signal traces connected to built-in electronic hardware.

Claims

1. 1. An apparatus, comprising: a deployable element configured to be deployed subcutaneously; an introducer configured to remain adjacent to the deployable element during deployment of the deployable element to support the deployable element during deployment; a base having an opening through which the deployable element and the introducer are configured to extend; The device, wherein the deployable element is configured to extend into the user's skin a first amount during deployment, and the introducer is configured to penetrate and extend into the user's skin a second amount less than the first amount.

2. The device of claim 1 , wherein the deployable element is configured to extend into the user's skin to a depth of 4-7 mm.

3. The device of claim 1 , wherein the introducer is configured to penetrate the outermost layer of the user's skin, including the stratum corneum through the dermis layer.

4. The device of claim 1 , wherein the introducer is configured to extend into the user's skin to a depth of 1 to 3 mm.

5. The device of claim 1 , wherein the introducer is configured to automatically retract through the opening in the base after reaching a maximum deployed distance.

6. The device of claim 1 , wherein the deployable element is configured to continue extending even after the introducer reaches a maximum deployed distance.

7. The device of claim 1 , wherein the deployable element is selected from the group consisting of a cannula, a conduit, a needle, or a sensor.

8. The deployable element comprises: a glucose sensor configured to perform continuous glucose monitoring; or 10. The device of claim 1, which is a ketone sensor.

9. 10. The device of claim 1, further comprising a rotation mechanism having a periphery around which the deployable element is wrapped at least in part, the rotation mechanism configured to rotate the deployable element around the periphery and configured to selectively constrain the deployable element such that the rotation of the deployable element is converted into linear motion.

10. 10. The device of claim 9, further comprising an introducer spring coiled about a fixed point on the device.

11. The device comprises: a cowling that houses at least a portion of the rotation mechanism; a retention block configured to secure the introducer to the cowling; The device of claim 10 , further comprising one or more escapement clips disposed in corresponding recesses in the retention block and configured to secure the introducer spring.

12. The device of claim 10 , wherein the introducer spring comprises an introducer spring interface configured to engage a corresponding interface on the introducer.

13. The apparatus of claim 9 , wherein the rotation mechanism is a sheave assembly.

14. The apparatus of claim 9 , further comprising a torsion spring configured to provide energy to rotate the rotation mechanism.

15. The device of claim 9 , further comprising a stop plate configured to control the extent to which the deployable element extends beyond the opening.

16. The device of claim 9 , further comprising a fluid conduit configured to connect the deployable element to a reservoir.

17. The device of claim 1 , further comprising a linear deployment mechanism configured to extend the deployable element and the introducer.

18. 10. The device of claim 1, further comprising at least one convex or concave protrusion on the base, the protrusion being sized and shaped to tension a user's skin near the opening when the base is pressed against the skin.

19. The device of claim 1 , wherein the deployable element has a layered construction including at least one polymer, at least one metal, and a coating.

20. The device of claim 1 , wherein the deployable element comprises one or more conductive signal traces connected to embedded electronic hardware.

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