Wearable medical devices, applicators therefor, and methods of use thereof

Abstract

Wearable medical devices having a plurality of microneedles on a first rotationally different section and a plurality of microneedles on a second rotationally different section are described. Applicators and methods for attaching a wearable medical device to a skin surface are also described.

Description

BACKGROUND

[0001] The wearable medical device and / or fitness monitoring device industry is growing. People are increasingly interested in monitoring their health and sharing their health data remotely with a physician or emergency personnel. Many current devices that monitor parameters such as heart rate, blood pressure, oxygen saturation, etc. are in the form of wearable accessories, such as watches, bands, rings, chest bands, etc. However, not all parameters can be measured in this way, and these wearable devices are not sufficiently discreet. For example, continuous glucose monitoring via a device adhered to the skin is increasingly popular among diabetics, and even among people following a low-carb diet. However, the adhesive required to wear such devices often causes skin damage and infection, especially in elderly users. Adhesives are also known to cause allergic reactions in some individuals, which can be severe enough to prevent some patients from using these devices.

[0002] What is needed is a way to secure a monitoring device to the skin without the need to use an adhesive. SUMMARY

[0003] In one embodiment, a wearable medical device is described. The wearable medical device includes a base having a first rotationally distinct segment and a second rotationally distinct segment. The second rotationally distinct segment at least partially surrounds the first rotationally distinct segment. The wearable medical device further includes at least one communication member in communication with the first rotationally distinct segment and the second rotationally distinct segment, a plurality of first microneedles located on the first rotationally distinct segment, and a plurality of second microneedles located on the second rotationally distinct segment.

[0004] In one embodiment, an applicator for attaching a wearable medical device of the present disclosure to a skin surface is described. The applicator includes a loading actuator configured to counter-rotationally load the first rotationally distinct segment and the second rotationally distinct segment, a retaining element to retain the wearable medical device in the counter-rotationally loaded configuration, and a mechanism to release the wearable medical device from the counter-rotationally loaded configuration.

[0005] In one embodiment, a method for attaching a wearable medical device of the present disclosure to a skin surface is described. The method includes rotating a first rotationally distinct segment and rotating a second rotationally distinct segment such that the wearable medical device is in a counter-rotationally loaded configuration, contacting the wearable medical device in the counter-rotationally loaded configuration to the skin surface, and releasing the wearable medical device from the counter-rotationally loaded configuration such that a plurality of first microneedles and a plurality of second microneedles are driven into the skin surface.

[0006] In one embodiment, a method for monitoring a biological signal is described. The method includes detecting the biological signal with a monitoring device secured to a wearable medical device of the present disclosure, the wearable medical device attached to a skin surface.

[0007] In one embodiment, a kit is described. The kit includes a wearable medical device of the present disclosure and a set of instructions for attaching the wearable medical device to a skin surface. BRIEF DESCRIPTION OF DRAWINGS

[0008] The following detailed description of various embodiments of the present disclosure can be more fully understood when considered in conjunction with the accompanying drawings.

[0009] FIG. 1A is a bottom side view of a wearable medical device of the present disclosure.

[0010] FIG. 1B is a top view of the wearable medical device of FIG. 1A

[0011] FIG. 2A is a top side view of a wearable medical device of the present disclosure.

[0012] FIG. 2B is a top view of the wearable medical device of FIG. 2A

[0013] FIG. 3A is a bottom side view of a wearable medical device of the present disclosure.

[0014] FIG. 3B is a top view of the wearable medical device of FIG. 2A

[0015] FIG. 4 shows a side view and an angle of elevation measurement of a microneedle of the present disclosure.

[0016] FIG. 5 shows a top view and an angle of orientation measurement of a microneedle of the present disclosure.

[0017] FIG. 6A shows an applicator of the present disclosure with a wearable medical device inserted.

[0018] FIG. 6B shows an applicator of the present disclosure with a wearable medical device in a reverse rotationally loaded configuration.

[0019] FIG. 7A is a top view of a wearable medical device with a mechanical actuator in an unloaded configuration.

[0020] FIG. 7B ​​​is a top view of a wearable medical device with a mechanical actuator in a loaded configuration.

[0021] Reference is made in the following description to the accompanying drawings. Various embodiments can be provided by way of illustration of the disclosure. It should be understood that structural changes can be made without departing from the scope of the disclosure. The drawings are not necessarily to scale. Like numbers refer to like parts throughout the several views of the drawings. DETAILED DESCRIPTION

[0022] The present disclosure describes wearable medical devices that can be affixed to the skin via microneedles. The wearable medical devices utilize opposing forces between rotating sections to not only drive the microneedles into the skin, but also to affix the microneedles within the skin. Relative to similar devices that adhere to the skin via adhesive, wearable medical devices that attach to the skin via microneedles are more resistant to accidental shedding and are worn for longer periods of time. Furthermore, the wearable medical devices of the present disclosure are painless to attach, painless to wear, and do not cause skin damage or adverse reactions that often accompany adhesives. Additionally, the wearable medical devices of the present disclosure allow for air flow underneath the device to prevent the growth of bacteria due to moisture accumulation and also allow for cleaning.

[0023] While the wearable medical devices can include permanent monitoring devices thereon, the wearable medical devices of the present disclosure are primarily intended to be used as a base for affixing removable monitoring devices thereon. The user can enjoy the flexibility of a modular system. Definitions

[0024] As used herein, the term“about” means ±10% of a given value. For example, about 10 means 9 to 11.

[0025] As used herein, the term“adhesive” as used herein refers to a polymeric composition that adheres two adherends together. Examples of adhesives are pressure sensitive adhesives and gel adhesives.

[0026] As used herein, the term“actuation guide” refers to a feature on or within a component of an applicator that is complementary to an applicator guide within the wearable medical device. In the manner of rotation within the applicator, the cooperation of the actuation guide and the applicator guide effectively rotates the first rotationally distinct section and / or the second rotationally distinct section within the wearable medical device.

[0027] As used herein, the term "applicator guide" or "application guide" refers to a feature on or within a component of a wearable medical device that is complementary to an actuation guide within an applicator. In a manner that is rotational within the applicator, the mating of the applicator guide and the actuation guide effectively rotates a first rotationally distinct section and / or a second rotationally distinct section within the wearable medical device.

[0028] As used herein, the term "barb" describes a feature on a microneedle body that extends outward at an angle from the microneedle body. A barbed needle can be more difficult to remove from a skin surface than a non-barbed needle. Also, a barbed needle can prevent full penetration as compared to a non-barbed needle. A barbed needle can increase attachment, thereby extending wear time. A barbed needle can also help achieve a desired gap between the wearable medical device and the skin surface.

[0029] As used herein, "center" refers to the point where two perpendicular planes intersect and each of the areas in the respective quadrants are equal. For example, the center of a microneedle base is the center of the area in contact with the respective rotationally distinct section.

[0030] As used herein, the term "communicating member" refers to a substance that connects a first rotationally distinct section and a second rotationally distinct section, but the substance does not prevent independent rotation of the first rotationally distinct section and the second rotationally distinct section. As used herein, the term "tensioning communicating member" refers to an article that connects a first rotationally distinct section and a second rotationally distinct section, wherein the article deforms and stores potential energy when the first rotationally distinct section and the second rotationally distinct section are rotated, and the potential energy is converted to kinetic energy when the article is allowed to at least partially return to its original state. As used herein, a "rolling communicating member" refers to a rotational article that is at least partially located between a first rotationally distinct section and a second rotationally distinct section, wherein the rotational article is accordingly rotated when the first rotationally distinct section and the second rotationally distinct section are rotated.

[0031] As used herein, the term "counter-rotationally" is used to describe the manner in which a first rotationally distinct section and a second rotationally distinct section rotate relative to each other. One section rotates clockwise and the other section rotates counterclockwise.

[0032] As used herein, "flexible" describes an article that can be stretched, bent, compressed, or otherwise twisted under the action of a force, but at least partially returns to an unstretched, unbent, uncompressed, or untwisted state when the force is removed.

[0033] As used herein, the term "microneedle" refers to a microstructured protrusion having a tip configured to penetrate the skin.

[0034] As used herein, “rotate” refers to moving about an axis of rotation by some degree.

[0035] As used herein, the phrase “rotationally distinct” describes a component that can rotate independently of another component. For example, two rotationally distinct components that are otherwise connected can be able to rotate in opposite directions to some degree. BRIEF DESCRIPTION OF DRAWINGS

[0036] FIG. 1A is a bottom view of a wearable medical device 100 of the present disclosure, showing a first major surface of a base 102. The wearable medical device 100 includes the base 102 including a first rotationally distinct segment 104 having a plurality of first microneedles 106 thereon and a second rotationally distinct segment 108 having a plurality of second microneedles 110 thereon. The first and second rotationally distinct segments 104, 108 are shown in the shape of concentric cylindrical rings connected by a (tensioned) communication member 112 (shown here as a flexible rod or band). The communication member 112 is depicted as connecting the first and second rotationally distinct segments 104, 108 in a non-radial manner. During application, a loading actuator (not shown) rotates the first rotationally distinct segment 104 in a direction opposite the first microneedle 106 tips (shown here as clockwise) and the second rotationally distinct segment 108 in a direction opposite the second microneedle 110 tips (shown here as counterclockwise), thereby contracting the communication member 112. The communication member 112 stretches as the first and second rotationally distinct segments are rotated. Alternative arrangements in which the communication member 112 otherwise flexes can be readily envisioned. Retaining elements (not shown) hold the respective rotationally distinct segments 104 / 108 in the oppositely rotatingly loaded configuration. Upon contact with the skin, the retaining elements (not shown) can disengage to release the wearable medical device 100, with the oppositely directed first and second microneedles 106 / 110 each driven into the skin surface by the (tensioned) communication member 112 at least partially returning to a relaxed state.

[0037] FIG. 1B is FIG. 1A is a top view of the wearable medical device 100 of

[0038] FIG. 2Ais a top side view of the wearable medical device 200 of the present disclosure, showing the first major surface 202a and the second major surface 202b of the base 202. The wearable medical device 200 includes a base 202 that includes a first rotationally distinct section 204 having a plurality of first microneedles 206 thereon and a second rotationally distinct section 208 having a plurality of second microneedles 210 thereon. The first rotationally distinct section 204 and the second rotationally distinct section 208 are shown in the shape of concentric cylindrical rings that are in mechanical communication by a (rolling) communication member 212 (shown here as a rolling disc). During application, a drive actuator (not shown) causes the first rotationally distinct section 204 to rotate in a direction that aligns with the first microneedle 206 tips (shown here as clockwise) and the second rotationally distinct section 208 to rotate in a direction that aligns with the second microneedle 210 tips (shown here as counterclockwise), thereby causing the communication member 212 to roll. Upon contact with the skin, the drive actuator drives the first and second microneedles 206 / 210 into the skin surface.

[0039] FIG. 2B is FIG. 2A a top view of the wearable medical device 200, showing the second major surface of the base 202. The first rotationally distinct section 204 and the second rotationally distinct section 208 are shown in the shape of concentric cylindrical rings that are in mechanical communication by a (rolling) communication member 212.

[0040] FIG. 3Ais a bottom side view of a wearable medical device 300 showing a first major surface 302a and a second major surface 302b of a base 302. The wearable medical device 300 includes the base 302 comprising a first rotationally distinct section 304 with a plurality of first microneedles 306 thereon and a second rotationally distinct section 308 with a plurality of second microneedles 310 thereon. The first and second rotationally distinct sections 304 / 308 are shown in the shape of concentric cylindrical rings, and the respective microneedles 306 / 310 are each in flush rows. The wearable medical device 300 further includes a flexible film 311 in contact with the second major surface 302b. The flexible film 311 is adhered to the first and second rotationally distinct sections 304 / 308 and acts as a (tensioned) communication member 312 therebetween. During application, a loading actuator (not shown) rotates the first rotationally distinct section 304 in a direction opposite the first microneedle 306 tips (here shown counterclockwise) and the second rotationally distinct section 308 in a direction opposite the second microneedle 310 tips (here shown clockwise), thereby stretching the flexible film 311 / communication member 312 therebetween. A retention element (not shown) retains the respective rotationally distinct sections 304 / 308 in the oppositely rotatingly loaded configuration. Upon contact with the skin, a release element (not shown) can disengage to release the wearable medical device 300, with the opposite first and second microneedles 306 / 310 driven into the skin surface by the flexible film 311 / communication member 312 at least partially returning to a relaxed state.

[0041] FIG. 3B is FIG. 1AA top view of the wearable medical device 300 in FIG. 3 is shown with the second major surface of the base 302. A portion of the flexible membrane 311 / communicating member 312 can be observed between the in-laid backing 314 covering the first rotationally distinct segment (not shown) and the out-laid backing 316 covering the second rotationally distinct segment (not shown). The in-laid backing 314 is shown with in-applied guides 318 and the out-laid backing 316 is shown with out-applied guides 320. During application, a loading actuator (not shown) rotates the first rotationally distinct segment (not shown) in one direction (here shown as clockwise) by communicating with the in-laid backing 314 / in-applied guides 318 and rotates the second rotationally distinct segment (not shown) in the opposite direction (here shown as counter-clockwise) by communicating with the out-laid backing 316 / out-applied guides 320. In effect, the flexible membrane 311 / communicating member 312 is stretched or otherwise twisted. Retaining elements (not shown) hold the respective rotationally distinct segments in the oppositely rotatingly loaded configuration. Upon contact with the skin, the retaining elements (not shown) can disengage to release the wearable medical device 300 with the first microneedles and the second microneedles (not shown) driven into the skin surface by the flexible membrane 311 / communicating member 312 at least partially returning to a relaxed state.

[0042] FIG. 4 A side view of an example first microneedle 406 (or second microneedle) of the present disclosure is shown. The first microneedle 406 is shown with a microneedle base 422 in contact with the first rotationally distinct segment 404. The microneedle base 422 extends into a microneedle body 424 and terminates at a microneedle tip 426. The first microneedle 406 is shown at an elevation angle 428 (“θ EA ”). The elevation angle 428 is measured relative to a plane B passing through the center of the microneedle base 422 from a plane A parallel to the surface in which the first microneedle 406 is in contact with the first rotationally distinct segment 404 to the microneedle tip 426 (see plane C). — Plane A and plane B are perpendicular to each other, i.e., 90°.

[0043] FIG. 5 A top view of the first rotationally distinct segment 504 (or second microneedle on the second rotationally distinct segment) of the present disclosure with a plurality of first microneedles 506 disposed thereon is shown. Each of the plurality of first microneedles 506 is independently disposed at an orientation angle 530 (“θ OA ”). The orientation angle 530 is measured relative to a radial plane D and a tangential plane E (i.e., the tangential plane E is tangent to the radial plane D, i.e., 90°). Plane F is parallel to plane E and is used for visual aid only. Each radial plane D passes through the center of the microneedle base 522 (see FIG. 4plane B, i.e., the radial plane D in the z-direction normal to plane B; tangential planes E and F in the x-direction). The first microneedle 506a aligned with the tangential planes E and F has an orientation angle 530, i.e., Θ OA = 0°. The first microneedle 506b angled toward the axis of rotation is characterized by an orientation angle 530, i.e., Θ OA < 0°, e.g., -10°. The first microneedle 506c angled away from the axis of rotation is characterized by an orientation angle 530, i.e., Θ OA > 0°, e.g., 10°. The description need not be limited to circular configurations.

[0044] FIG. 6A An example applicator 601 is shown with an inserted wearable medical device 600 in an unloaded configuration. The applicator 601 is shown to include a first segment actuation guide 603 within an inner wall 605 that cooperates with a first applicator guide 607 on a first rotationally distinct segment 604. The applicator 601 is also shown to include a second segment actuation guide 609 within an outer wall 611 that cooperates with a second applicator guide 613 on a second rotationally distinct segment 608.

[0045] FIG. 6B An example applicator 601 is shown with a wearable medical device 600 in a reverse rotationally loaded configuration. The first rotationally distinct segment 604 has been rotated clockwise and the second rotationally distinct segment 608 has been rotated counterclockwise. The applicator 601 holds the wearable medical device 600 in this reverse rotationally loaded configuration (hold elements not shown) until the applicator 601 contacts a skin surface. Upon disengaging the hold elements (not shown), the wearable medical device 600 is released from the loaded configuration and the plurality of microneedles on each segment are driven into the skin surface.

[0046] FIG. 7AA top view (second major surface) of a wearable medical device 700 with a set of mechanical actuators 732a / 732b is shown, with the medical device shown in an unloaded configuration. The wearable medical device 700 includes a base 702 with a first rotationally distinct segment 704, a second rotationally distinct segment 708, and a communication member 712. A first mechanical actuator 732a is in communication with the first rotationally distinct segment 704, and a second mechanical actuator 732b is in communication with the second rotationally distinct segment 708. Upon squeezing the mechanical actuators 732a / 732b together, the first rotationally distinct segment 704 rotates counterclockwise, and the second rotationally distinct segment 708 rotates clockwise. The mechanical actuators 732a / 732b can be used to attach the wearable medical device to a skin surface or remove the wearable medical device from a skin surface.

[0047] FIG. 7B A top view of a wearable medical device 700 with a set of mechanical actuators 732a / 732b is shown, with the medical device shown in a loaded configuration. In contrast to the unloaded configuration of FIG. 7A The communication member 712 is shown as stretched compared to the unloaded configuration. Wearable medical device

[0048] In various embodiments, a wearable medical device is described. The wearable medical device can include a base having a first rotationally distinct segment and a second rotationally distinct segment. The second rotationally distinct segment can at least partially surround the first rotationally distinct segment. At least one communication member can be in communication with the first rotationally distinct segment and the second rotationally distinct segment. The wearable medical device can also include a plurality of first microneedles on the first rotationally distinct segment and a plurality of second microneedles on the second rotationally distinct segment.

[0049] Further details and further features of the wearable medical device are described below. It should be understood that the details and features described below can be incorporated, either individually or in combination, unless otherwise stated. Base

[0050] The base and all components within the base can be characterized by a first major surface and a second major surface. The first major surface is considered the skin contact surface, while the second major surface is opposite the first major surface and does not contact the skin when the wearable medical device is in use. Thus, all first microneedles and second microneedles described herein are on the first major surface of the base.

[0051] In some embodiments, the base can further include one or more applicator guides for mating with an applicator, the applicator guides configured for rotating the first rotationally distinct segment and the second rotationally distinct segment. For example, the applicator guides can be in the form of one or more notches, protrusions, pins, pin holes, etc., where the applicator guides can complement actuation guides within an applicator. The applicator guides can be located on the second major surface, along the perimeter (minor surface), or a combination thereof.

[0052] In some embodiments, the base can further include one or more monitoring device securing features for attaching a monitoring device to the wearable medical device. Example monitoring device securing features can include a clip, a hook, a latch, a cradle, a threaded component for mating with a threaded monitoring device, an adhesive, or a combination thereof, etc. The monitoring device securing features can be located on the second major surface, along the perimeter (minor surface), or a combination thereof.

[0053] In some embodiments, the base can further include a first mechanical actuator in communication with the first rotationally distinct segment, and a second mechanical actuator in communication with the second rotationally distinct segment. FIG. 7A and FIG. 7B Example mechanical actuation of a wearable medical device is shown without the use of an applicator as described herein. While FIG. 7A and FIG. 7B Reversing the loading of a wearable medical device (i.e., the mechanical actuators are pushed together) is also contemplated. For example, a wearable medical device with rolling communication members (e.g., FIG. 2A ) can include mechanical actuators that can be used to drive the plurality of microneedles into a skin surface (i.e., the mechanical actuators are pushed apart).

[0054] In some embodiments, with or without an applicator as described herein, the mechanical actuators can be used to apply and / or remove the wearable medical device to / from a skin surface. While the mechanical actuators are not necessary for the use of an applicator as described herein, the applicator can be configured to actuate the mechanical actuators. In other words, any such mechanical actuators can be considered “applicator guides” as used herein when combined with an applicator.

[0055] In some embodiments, the base can further include a flexible film adhered to or otherwise connected to the second major surface and extending at least from the first rotationally distinct segment to the second rotationally distinct segment such that the first rotationally distinct segment can be in communication with the second rotationally distinct segment (i.e., a communication member). In some embodiments, the flexible film can span the entire second major surface of the base. In some embodiments, the flexible film can extend beyond the perimeter of the base. A base having a flexible film extending beyond the perimeter of the base can further include adhesive thereon that can be used as an auxiliary skin attachment modality.

[0056] In some embodiments, the flexible film can be composed of a material such as a woven (e.g., cotton, rayon, polyvinyl chloride, polyethylene, or polyurethane), latex, or the like. In some embodiments, the flexible film can be breathable and water resistant.

[0057] In some embodiments, the flexible film can further include adhesive on one or more surfaces. In some embodiments, suitable adhesive can be composed of acrylate, methacrylate, epoxy diacrylate, or the like. The adhesive can be located on a surface that contacts the skin surface when applied and thus serves as an auxiliary means of securing the wearable medical device to the skin. The adhesive can be located on a surface that is opposite the skin surface when applied and can serve as a means of attaching the placement backing and / or the monitoring device (i.e., monitoring device securement feature). In some embodiments, the flexible film can be in the form of a double-sided tape.

[0058] In many embodiments, the flexible film can be light transmissive. In many embodiments, the flexible film can be composed of a material that is easily punctured (e.g., by a needle). In other embodiments, the flexible film can include regions devoid of material for passage of a needle (e.g., extending from a mounted glucose monitor device), light (e.g., emitted from a mounted oximeter device), electrode, or some other skin contacting or penetrating probe.

[0059] In many embodiments, the base can further include a flexible film as described herein and one or more placement backings. The one or more placement backings can be reversibly or irreversibly adhered to the flexible film with adhesive or can otherwise be sewn thereto. The placement backings can include application guides configured to cooperate with loading actuators within the applicator. In some embodiments, the placement backings can include an inner placement backing configured to rotate the first rotationally distinct segment (e.g., by inner application guides) and an outer placement backing at least partially surrounding the inner placement backing configured to rotate the second rotationally distinct segment (e.g., by outer application guides). Rotating different sections

[0060] In many embodiments, the first rotationally distinct segment and the second rotationally distinct segment can be arranged such that they share a common axis of rotation. While separate axes of rotation are conceivable and are intended to be encompassed by the scope of the present disclosure, a shared axis of rotation is the simplest and most elegant construction.

[0061] In many embodiments, the first rotationally distinct segment and the second rotationally distinct segment are configured for rotation in opposite directions (i.e., clockwise and counterclockwise relative to one another), wherein the rotation induces a stress within a stress-communicating member in communication with each segment. The stress can be in the form of tension, compression, torsion, bending, winding, twisting, rotation, etc. The applicator or other applicator device of the present disclosure can be configured to fix the first rotationally distinct segment and the second rotationally distinct segment in a state of rotation and to bear the potential energy within the stress-communicating member. The kinetic energy provided by the release of the stress within the stress-communicating member is effective to cause the rotationally distinct segments to remove rotation, such that the microneedles on the segments can be driven into the skin under some force.

[0062] The first rotationally distinct segment and the second rotationally distinct segment can independently have any size and shape, so long as either segment does not impede the rotation of the other segment. Example shapes include a full cylinder or half-cylinder, an elliptical cylinder, a conical frustum, a rectangle, a square, a truncated cone, etc.; the shape can be solid or annular (i.e., ring-shaped). An annular shape of the first rotationally distinct segment can allow light from a mounted monitoring device to pass through, or other physical contact between the skin surface and a mounted monitoring device. In some embodiments, the first rotationally distinct segment and the second rotationally distinct segment can each be a cylindrical ring (i.e., a washer) and arranged in a concentric manner. In other embodiments, the first rotationally distinct segment can be a solid cylinder and the second rotationally distinct segment can be a cylindrical ring arranged in a concentric manner. Some shapes can be more suitable for different applications, e.g., to accommodate different areas of the body, to accommodate different shapes of monitoring devices, etc.

[0063] In many embodiments, the first rotationally distinct segment and the second rotationally distinct segment are arranged such that at least one major surface of each of the segments is flush with one another. In embodiments in which the first rotationally distinct segment and the second rotationally distinct segment do not include at least one major surface of each of the segments that are flush with one another, the wearable medical device will require the first microneedles and the second microneedles to be unequal in length, so that each set of microneedles can contact the skin.

[0064] In some embodiments, the first and second rotationally distinct segments can each independently be characterized by a maximum length and a maximum width of about 5 mm to about 75 mm. For example, the maximum length and / or maximum width can be selected from a value (in mm) in a range of about 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, or 75, or between any of the foregoing values (e.g., between about 25 and about 40, etc.).

[0065] In some embodiments, the first and second rotationally distinct segments can each independently be characterized by an average thickness of about 1 mm to about 10 mm. For example, the average thickness can be selected from a value (in mm) in a range of about 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, or 10, or between any of the foregoing values (e.g., between about 3 and about 8, etc.).

[0066] In many embodiments, the first and second rotationally distinct segments can each include at least 10 microneedles thereon. In some embodiments, the first and second rotationally distinct segments can each independently include 10 to 500 microneedles thereon. For example, the first and second rotationally distinct segments can each independently include a number of microneedles in a range of 10, 20, 30, 40, 50, 60, 70, 80, 90, 100, 125, 150, 175, 200, 225, 250, 275, 300, 325, 350, 375, 400, 425, 450, 475, or 500, or between any of the foregoing values (e.g., between about 50 and about 100, etc.). The number of needles in each rotationally distinct segment can be selected according to various factors, such as the intended device placement, skin type, activity level of the user, intended wear time, etc.

[0067] In some embodiments, the first rotationally distinct segment can include one or more first applicator guides configured to cooperate with one or more actuator guides within an applicator described herein. The one or more first applicator guides can be located on an inner circumference (minor surface) of the first rotationally distinct segment. In some embodiments, the second rotationally distinct segment can include one or more second applicator guides configured to cooperate with one or more actuator guides within an applicator described herein. The one or more second applicator guides can be located on an outer circumference (minor surface) of the second rotationally distinct segment. In some embodiments, the first and second applicator guides can independently be in the form of notches, protrusions, pins, pin holes, etc.

[0068] In some embodiments, the first rotationally distinct segment and the second rotationally distinct segment can be composed of a material selected from a metal, a plastic, or a combination thereof.

[0069] In some embodiments, the wearable medical device can have only two rotationally distinct segments. In other embodiments, the wearable medical device can have more than two rotationally distinct segments, where any additional rotationally distinct segments can be characterized in a similar manner as any of the rotationally distinct segments described herein. Communicating member

[0070] In some embodiments, the communication member can be a tension communication member selected from a flexible rod or band, a spring, a flexible membrane (as described above), a combination thereof, or the like. In other embodiments, the communication member can be a rolling communication member, such as a rolling disc.

[0071] In some embodiments, the communication member can be in the form of a flexible rod, a flexible band, or a spring.

[0072] In many embodiments, the communication member can at least partially connect the first rotationally distinct segment and the second rotationally distinct segment via a minor surface (e.g., an inner wall or an outer wall of a rotationally distinct segment shaped as a ring). In some embodiments, the communication member can at least partially connect the first rotationally distinct segment and the second rotationally distinct segment via a major surface (e.g., a second major surface opposite a first major surface having microneedles).

[0073] In some embodiments, the wearable medical device can include one or more communication members in the form of a flexible rod or band extending from an outer wall of a first rotationally distinct segment shaped as a ring and an inner wall of a second rotationally distinct segment shaped as a ring. In some embodiments, the flexible rod or band can extend radially (i.e., parallel to a radius) between the first rotationally distinct segment and the second rotationally distinct segment. In other embodiments, the flexible rod or band can extend non-radially (e.g., at an angle relative to a radial plane) between the first rotationally distinct segment and the second rotationally distinct segment. The non-radial arrangement can be measured according to one end of the communication member on a radial plane and the other end of the communication member measured at an angle (°) of about 1° to 45° (e.g., 1, 2, 5, 8, 10, 12, 15, 18, 20, 22, 25, 28, 30, 32, 35, 38, 40, 42, or 45 degrees or a range between any of the foregoing values (e.g., between about 20 and about 40)) relative to the radial plane. The flexible rod or band in a non-radial arrangement can be positioned in one of two orientations (i.e., / and \), and depending on the direction of rotation of the rotationally distinct segments, the flexible rod or band can be stretched or bent.

[0074] In some embodiments, the type of communication member and the number of communication members present in the wearable medical device of the present disclosure can be selected according to the desired kinetic energy for driving the rotation of the different segments. For example, the wearable medical device can be customized for the type of skin surface to which the device is to be applied, which can require more or less force to adequately or safely install the wearable medical device into the skin surface.

[0075] In some embodiments, the wearable medical device can include from 1 to 20 (e.g., 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 15, 18, or 20 or a value ranging between any of the foregoing values (e.g., between 2 and 6, etc.)) communication members. In some embodiments, each of the communication members is the same type. In other embodiments, a mix of communication members can be present within the wearable medical device. Microneedle

[0076] In many embodiments, the first microneedles and the second microneedles can be arranged in a circular or semi-circular array extending around the axis of rotation, regardless of the shape of the first rotationally distinct segment and the second rotationally distinct segment. In many embodiments, the plurality of first microneedles can be arranged in one or more rows along the first rotationally distinct segment. Likewise, the plurality of second microneedles can be arranged in one or more rows in a circular path along the second rotationally distinct segment. In some embodiments, the rows can be flush with adjacent rows or can be staggered. In some embodiments, each of the plurality of first microneedles and second microneedles can be arranged in 1 to 5 rows, e.g., 1, 2, 3, 4, or 5 rows, e.g., 2 to 3 rows.

[0077] In some embodiments, the plurality of first microneedles and second microneedles can be arranged in rows, and each microneedle can be independently separated from one another by a distance of about 1 mm to about 10 mm. For example, any of the microneedles can be separated by a distance of about 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, or 10 or a value ranging between any of the foregoing values (e.g., between about 4 and about 6, etc.) in mm.

[0078] In embodiments having more than one row, the rows can be independently separated by a distance of about 5 mm to about 10 mm. For example, the rows can be independently separated by a distance of about 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, or 10 or a value ranging between any of the foregoing values (e.g., between about 6 and about 8, etc.) in mm.

[0079] In some embodiments, each of the first microneedles and the second microneedles can independently be characterized by an elevation angle of from about 40° to about 80° relative to a plane to which the microneedle is attached (i.e., the respective rotationally distinct segment). For example, the first microneedles and the second microneedles can independently be characterized by an elevation angle of about 40, 42, 45, 48, 50, 52, 55, 58, 60, 62, 65, 68, 70, 72, 75, 78, or 80, or a value within a range between any of the foregoing values (e.g., between about 45 and about 50, etc.) (°). For reference, a microneedle that is perpendicular to a parallel plane that passes through the respective rotationally distinct segment is characterized by an elevation angle of 90°. Elevation angles that are not within the above-mentioned range are still within the scope of the present disclosure; however, it is believed that the above-mentioned range can provide benefits to the user in terms of pain reduction, skin health maintenance, and longer wear times. Obviously, depending on the point of reference, any elevation angle can be measured as an acute or an obtuse angle. Thus, the above-mentioned elevation angles can be considered as their obtuse angle counterparts (i.e., from about 140° to about 100°, respectively, and all angles therebetween). The elevation angle is measured from a parallel plane that passes through the respective rotationally distinct segment to the center of the microneedle tip relative to a plane that is perpendicular to the parallel plane and passes through the center of the microneedle base.

[0080] In many embodiments, each of the first microneedles can be characterized by the same elevation angle. In other embodiments, at least a portion of the first microneedles can be characterized by one elevation angle, and at least another portion of the first microneedles can be characterized by another elevation angle. In some cases, a mix of elevation angles can be beneficial for tailoring the wearable medical device to the intended area of the body on which the wearable medical device is to be worn. In many embodiments, each of the second microneedles can be characterized by the same elevation angle. Likewise, in other embodiments, at least a portion of the second microneedles can be characterized by one elevation angle, and at least another portion of the second microneedles can be characterized by another elevation angle. In some embodiments, each of the first microneedles and the second microneedles can be characterized by the same elevation angle, or some portion of the first microneedles or the second microneedles can be characterized by a different elevation angle.

[0081] In embodiments having at least a portion of first microneedles characterized by an elevation angle other than 90°, these elevation angle first microneedles must all point in the same rotational direction (i.e., all tips face clockwise or counterclockwise). Likewise, in embodiments having at least a portion of second microneedles characterized by an elevation angle other than 90°, these elevation angle second microneedles must all point in the same rotational direction. Further, in embodiments having both first and second microneedles characterized by an elevation angle other than 90°, the elevation angle first microneedles can be in opposite rotational directions relative to the elevation angle second microneedles. In other words, each first microneedle characterized by an elevation angle other than 90° (e.g., 40° to 80°) can be oriented such that the first microneedle tip faces in one rotational direction, and each second microneedle characterized by an elevation angle other than 90° (e.g., 40° to 80°) can be oriented such that the second microneedle tip faces in a rotational direction opposite the rotational direction of the first microneedle tip. When referring to opposite rotational directions, an implied shared rotational axis is suggested.

[0082] In some embodiments, each of the first and second microneedles characterized by an elevation angle other than 90° can be independently arranged to be at an orientation angle of about -25° to about 0° (aligned with the tangent) or about 0° (aligned with the tangent) to about 25° relative to a tangent of the rotational vector (i.e., the rotation of the respective rotationally distinct segment). Negative orientation angle values indicate that the needle points toward the rotational axis, while positive orientation angle values indicate that the needle points away from the rotational axis. For example, any given microneedle can be characterized by an orientation angle of a value (°) in a range of about -25, -22, -20, -18, -15, -12, -10, -8, -5, -2, 0, 2, 5, 8, 10, 12, 15, 18, 20, 22, or 25, or any of the foregoing values on either side of 0 (e.g., between about -15 and about -8, between about 5 and about 12, etc.). In many embodiments, each of the first and second microneedles can be arranged such that the entire needle body is aligned tangentially to the rotational vector (i.e., an orientation angle of 0°) relative to the rotation of the respective rotationally distinct segment. The orientation angle is measured from a tangential plane passing through the center of the microneedle base to the center of the microneedle tip. In other words, a microneedle parallel to the tangent of the rotational vector is characterized by an orientation angle of 0°. Further, for reference, a microneedle characterized by an orientation angle of 90° would be perpendicular to the rotational vector and would not be capable of piercing the skin surface at all during operation of the wearable medical device.

[0083] In some embodiments, each of the first microneedle and the second microneedle can independently be characterized by a length of about 0.2 mm to about 3.0 mm. For example, each of the first microneedle and the second microneedle can independently be characterized by a length of about 0.2, 0.5, 0.8, 1.0, 1.2, 1.5, 1.8, 2.0, 2.2, 2.5, 2.8, or 3.0 or a range between any of the foregoing values (e.g., between about 0.5 and about 0.8, etc.) in mm. The length of the needle can be selected as needed for the application. For example, shorter needles can be more comfortable for elderly users or for areas of the skin that can be thinner.

[0084] In some embodiments, each of the first microneedle and the second microneedle can independently be characterized by a diameter of about 1 pm to about 25 pm. For example, each of the first microneedle and the second microneedle can independently be characterized by a diameter of about 1, 2, 5, 8, 10, 12, 15, 18, 20, 22, or 25 or a range between any of the foregoing values (e.g., between about 8 and about 12, etc.) in pm. In some embodiments, any of the microneedles described herein can have a uniform diameter or a non-uniform diameter within the ranges described above. A non-uniform diameter can be characterized by a decreasing diameter along the microneedle body toward the tip. For example, a non-uniform diameter can decrease in diameter along the microneedle body toward the tip at a rate of about 5% to 25% (e.g., 5%, 8%, 10%, 12%, 15%, 18%, 20%, 22%, or 25%, or a range between any of the foregoing values (e.g., between 10% to about 15%, etc.)). A non-uniform diameter can also include regions within the microneedle body where the diameter can be larger, or isolated regions where the diameter can be larger. Such regions of larger diameter can be in the form of barbs. Microneedles having barbs can be used to better anchor the microneedle within the skin surface. Regions of larger diameter can also prevent the entire microneedle from penetrating the skin, effectively leaving a region between the skin surface and the base to allow air flow therebetween and prevent moisture accumulation and / or bacterial growth. In some embodiments, at least a portion of the first microneedle and / or the second microneedle can be characterized by a non-uniform diameter.

[0085] In many embodiments, it is desirable to leave a space between the skin surface and the wearable medical device such that airflow can prevent moisture buildup and bacterial growth. One way to accomplish this is to select microneedles that have a certain length and / or a certain diameter. In other words, the microneedles can only insert a certain percentage of the way into the skin. For example, the microneedles can insert 25% to 75% of the length of the skin, such as 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, or 75% of the length, or a value within a range between any of the foregoing values. In some embodiments, the wearable medical device can have a gap thickness of about 0.15 mm to about 1 mm (e.g., 0.15 mm, 0.2 mm, 0.25 mm, 0.3 mm, 0.35 mm, 0.4 mm, 0.45 mm, 0.5 mm, 0.55 mm, 0.60 mm, 0.65 mm, 0.7 mm, 0.75 mm, 0.8 mm, 0.85 mm, 0.9 mm, or 1 mm or a value within a range between any of the foregoing values) above the skin surface.

[0086] In some embodiments, any of the microneedles described herein can also include a microneedle base. The microneedle base can be any shape, but it is typically at least 25% larger than the diameter of the microneedle. The microneedle base can provide stability, but also serves to prevent the microneedle from inserting 100% into the skin surface, thereby leaving the desired gap between the skin surface and the wearable medical device. In some embodiments, the microneedle base can be the shape of a truncated or tapered-truncated cone.

[0087] In many embodiments, any of the microneedles described herein can be constructed from plastic, metal, absorbable material, or a combination thereof. Suitable plastics include polyolefin materials, polyesters, polyurethanes, and the like. Suitable metals include stainless steel, titanium, and nitinol (nickel / titanium alloy), and the like. Absorbable materials include those used to form absorbable sutures, such as polyglycolide (e.g., DEXON®), poly(glycolide / lactide) random copolymer (e.g., VICRYL®), and the like. ™ ™

[0088] In some embodiments, any of the microneedles described herein can be coated with one or more electrically conductive substances such that the wearable medical device can function as a dry electrode.

[0089] In some embodiments, any of the microneedles described herein can be solid or hollow. Hollow microneedles can allow passage of a therapeutic agent.

[0090] In some embodiments, each of the first microneedles and the second microneedles can be the same. In other embodiments, any of the first microneedles or any of the second microneedles can differ from one another in one or more of the aspects described above.​​ Applicator

[0091] In many embodiments, an applicator for attaching a wearable medical device of the present disclosure to a skin surface is described. The applicator can include a drive actuator configured to drive a first rotationally distinct segment and a second rotationally distinct segment in a counter-rotational manner. For example, an applicator with a drive actuator can be suitable for a wearable medical device described herein having a rolling communication member.

[0092] In many embodiments, an applicator for attaching a wearable medical device of the present disclosure to a skin surface is described. The applicator can include a load actuator configured to counter-rotationally load a first rotationally distinct segment and a second rotationally distinct segment, a retention element to retain the wearable medical device in the counter-rotationally loaded configuration, and a mechanism to release the wearable medical device from the counter-rotationally loaded configuration. For example, an applicator with a load actuator can be suitable for a wearable medical device described herein having a tensioning communication member.

[0093] In some embodiments, the load actuator can include any combination of mechanical components to effect rotation of the first rotationally distinct segment and the second rotationally distinct segment. For example, the load actuator can include one or more of a spring, a gear, a piston, a pump, etc. In some embodiments, the applicator can include a mechanism to engage the load actuator. For example, the mechanism can include twisting the applicator, retracting a plunger, etc.

[0094] In some embodiments, the load actuator can be tuned to a particular tensioning communication member or a particular number of communication members. For example, the load actuator can be configured to counter-rotationally load the wearable medical device with a selected degree of rotation such that the relaxation of the communication member is complete or incomplete once the wearable medical device is attached to the skin surface. Incomplete relaxation of the communication member once the wearable medical device is attached to the skin surface can be used to further secure the wearable medical device into the skin surface as the residual tension will continuously pull the opposing microneedles into the skin. However, excessive residual tension in the communication member while in the skin surface can cause damage. Conversely, the communication member can be over-extended upon application. In other words, a communication member that has relaxed beyond its original configuration can in fact be re-tensioned. An over-extended communication member can ultimately act to pull the microneedles out of the skin surface due to the force favoring return to its original configuration when the wearable medical device is attached to the skin surface, reducing wear time.

[0095] In some embodiments, the described applicator can also include a docking platform to retain the wearable medical device within the applicator.

[0096] In some embodiments, the described applicator can further include an actuation guide configured to cooperate with the applicator guide on the first rotationally distinct segment and the second rotationally distinct segment. Alternatively, the applicator can include a docking platform for holding the wearable medical device within the applicator, and an actuation guide configured to cooperate with the applicator guide on the docking platform. In some embodiments, the actuation guide can be a track within a fixed wall of the applicator. The track within the fixed wall of the applicator can be angled to accommodate rotation of the first rotationally distinct segment and / or the second rotationally distinct segment (see, e.g., FIGS. 1 1 A and 1 1 B). FIG. 6A and FIG. 6B ). The actuation guide can assist independent rotation of the first rotationally distinct segment and the second rotationally distinct segment, and thus can have any configuration. For example, the actuation guide can include a track, a pin, a gear, a friction inducing component, etc.

[0097] In some embodiments, the retaining element can include any combination of mechanical components for holding the first rotationally distinct segment and the second rotationally distinct segment in a counter-rotationally loaded configuration. For example, the retaining element can include a pin, a latch, a bracket, etc.

[0098] In some embodiments, the mechanism for releasing the wearable medical device from the counter-rotationally loaded configuration can include any combination of mechanical components for disengaging the retaining element. The mechanism can include a button, a compression plunger, a switch, etc. Upon disengaging the retaining element, the potential energy stored within the loaded communication member can drive the wearable medical device back to its original state, or at least partially to a relaxed state.

[0099] In some embodiments, the described applicator can further be configured for removing the wearable medical device from the skin surface. To remove the wearable medical device, the applicator can be brought into contact with the wearable medical device, and the loading actuator is engaged to effectively rotate the first rotationally distinct segment and the second rotationally distinct segment such that the first microneedles and the second microneedles are removed from the skin surface.

[0100] In some embodiments, features of the described applicator can be strictly mechanically driven. In other embodiments, features of the applicator can be at least partially electrically driven.

[0101] While the applicators described herein relate to assisting attachment of the wearable medical devices of the present disclosure, it should be understood that the described applicators can be used to attach wearable medical devices that can be outside the described scope, so long as the wearable medical devices include a first rotationally distinct segment, a second rotationally distinct segment, and a plurality of microneedles. Method of application

[0102] In many embodiments, a method for attaching a wearable medical device to a skin surface is described. The method can include providing a wearable medical device of the present disclosure (e.g., having a tensioned communication member), and rotating a first rotationally distinct segment and rotating a second rotationally distinct segment such that the wearable medical device is in a counter-rotationally loaded configuration. The method can include contacting the wearable medical device in the counter-rotationally loaded configuration to the skin surface, and releasing the wearable medical device from the counter-rotationally loaded configuration such that a plurality of first microneedles and a plurality of second microneedles are driven into the skin surface. In some embodiments, the rotation of the first rotationally distinct segment and the rotation of the second rotationally distinct segment can be via a mechanical actuator on the wearable medical device. In other embodiments, the rotation of the first rotationally distinct segment and the rotation of the second rotationally distinct segment can be via an applicator described herein.

[0103] In many embodiments, a method for attaching a wearable medical device to a skin surface is described. The method can include providing a wearable medical device of the present disclosure (e.g., having a rolling communication member); contacting the wearable medical device to the skin surface; and rotating a first rotationally distinct segment and rotating a second rotationally distinct segment such that a plurality of first microneedles and a plurality of second microneedles are driven into the skin surface. In some embodiments, the rotation of the first rotationally distinct segment and the rotation of the second rotationally distinct segment can be via a mechanical actuator on the wearable medical device. In other embodiments, the rotation of the first rotationally distinct segment and the rotation of the second rotationally distinct segment can be via an applicator described herein.

[0104] In many embodiments, a method for attaching a wearable medical device of the present disclosure (e.g., having a tensioned communication member) to a skin surface is described. The method can include providing an applicator described herein having the wearable medical device therein; and rotating a first rotationally distinct segment and rotating a second rotationally distinct segment such that the wearable medical device is in a counter-rotationally loaded configuration. The method can also include contacting the wearable medical device in the counter-rotationally loaded configuration to the skin surface; and releasing the wearable medical device from the counter-rotationally loaded configuration such that a plurality of first microneedles and a plurality of second microneedles are driven into the skin surface.

[0105] In many embodiments, a method for attaching a wearable medical device to a skin surface is described. The method can include providing an applicator described herein having a wearable medical device therein; and rotating the first rotationally distinct section and rotating the second rotationally distinct section such that the wearable medical device is in a counter-rotationally loaded configuration. The method can also include contacting the wearable medical device in the counter-rotationally loaded configuration with the skin surface; and releasing the wearable medical device from the counter-rotationally loaded configuration such that the plurality of microneedles are driven into the skin surface. The wearable medical device can be any wearable medical device so long as it includes a first rotationally distinct section, a second rotationally distinct section, and a plurality of microneedles.

[0106] In many embodiments, a method for attaching a wearable medical device of the present disclosure (e.g., having a rolling communication member) to a skin surface is described. The method can include providing an applicator described herein having the wearable medical device therein; contacting the applicator with the skin surface; and rotating the first rotationally distinct section and rotating the second rotationally distinct section such that the plurality of microneedles are driven into the skin surface. The wearable medical device can be any wearable medical device so long as it includes a first rotationally distinct section, a second rotationally distinct section, and a plurality of microneedles.

[0107] In many embodiments, a method for attaching a wearable medical device (e.g., having a rolling communication member) to a skin surface is described. The method can include providing an applicator described herein having the wearable medical device therein; contacting the applicator with the skin surface; and rotating the first rotationally distinct section and rotating the second rotationally distinct section such that the plurality of microneedles are driven into the skin surface. The wearable medical device can be any wearable medical device so long as it includes a first rotationally distinct section, a second rotationally distinct section, and a plurality of microneedles. The wearable medical device can be any wearable medical device so long as it includes a first rotationally distinct section, a second rotationally distinct section, and a plurality of microneedles.

[0108] In some embodiments, any of the methods described herein employing an applicator can also include selecting a degree of rotation for rotating the first rotationally distinct section and for rotating the second rotationally distinct section, whether it is for loading a wearable medical device (e.g., having a tensioning communication member) or driving a wearable medical device (e.g., having a rolling communication member).

[0109] In some embodiments, any of the methods described herein for attaching a wearable medical device can also include attaching a monitoring device to the wearable medical device.

[0110] In some embodiments, any of the methods described herein for attaching a wearable medical device to a skin surface can further comprise applying a supplemental fixation article to the wearable medical device or the wearable medical device having a monitoring device thereon. The supplemental fixation article can be a bandage, a protective covering (e.g., waterproof / sweatproof), etc. In some embodiments, the supplemental fixation article can comprise a backing and a skin-compatible adhesive.

[0111] In some embodiments, a method for removing a wearable medical device from a skin surface is described. The method can comprise engaging a mechanical actuator on the wearable medical device such that the wearable medical device is in a counter-rotationally loaded configuration; and lifting the wearable medical device from the skin surface.

[0112] In some embodiments, a method for removing a wearable medical device from a skin surface is described. The method can comprise contacting an applicator with a wearable medical device on a skin surface; engaging a loading actuator within the applicator such that the wearable medical device is in a counter-rotationally loaded configuration; and lifting the wearable medical device from the skin surface. Method of monitoring

[0113] In many embodiments, a method for monitoring a biological signal is described. The method can comprise detecting the biological signal with a monitoring device secured to a wearable medical device of the present disclosure attached to a skin surface.

[0114] In some embodiments, the biological signal can be selected from an electrical signal, a chemical signal, a light emission signal, or a combination thereof.

[0115] The method can further comprise attaching the wearable medical device to the skin surface.

[0116] The method can further comprise securing the monitoring device to the wearable medical device attached to the skin surface. Kit

[0117] In many embodiments, a kit is described. The kit can comprise a wearable medical device of the present disclosure and a set of instructions for attaching the wearable medical device to a skin surface. In some embodiments, the kit can further comprise one or more of: an applicator and a monitoring device.

[0118] In many embodiments, a kit is described. The kit can comprise a wearable medical device of the present disclosure, an applicator described herein, and a set of instructions for attaching the wearable medical device to a skin surface. In some embodiments, the kit can further comprise a monitoring device.

[0119] In some embodiments, any of the kits described herein can further include one or more supplemental securing articles.

Claims

1. A wearable medical device, the wearable medical device comprising: a base portion, the base portion comprising: a first rotationally distinct segment, a second rotationally distinct segment at least partially surrounding the first rotationally distinct segment, a plurality of first microneedles located on the first rotationally distinct segment, and a plurality of second microneedles located on the second rotationally distinct segment; and at least one communication member in communication with the first rotationally distinct segment and the second rotationally distinct segment.

2. The wearable medical device of claim 1, the base portion further comprising one or more monitoring device securing features for securing a monitoring device to the wearable medical device.

3. The wearable medical device of any one of claims 1-2, the base portion further comprising a first mechanical actuator in communication with the first rotationally distinct segment, and a second mechanical actuator in communication with the second rotationally distinct segment.

4. The wearable medical device of any one of claims 1-3, the base portion further comprising a flexible film extending beyond a perimeter of the base portion, the flexible film comprising an adhesive.

5. The wearable medical device of claim 4, the flexible film comprising one or more applicator guides thereon.

6. The wearable medical device of any one of claims 1-5, wherein the first rotationally distinct segment and the second rotationally distinct segment each take the shape of a cylindrical ring and are arranged in a concentric manner.

7. The wearable medical device of any one of claims 1-6, wherein each of the first rotationally distinct segment and the second rotationally distinct segment comprises one or more applicator guides.

8. The wearable medical device of any one of claims 1-7, wherein at least a portion of the plurality of first microneedles and at least a portion of the plurality of second microneedles are each independently characterized by an elevation angle of about 40° to 80°.

9. The wearable medical device of any one of claims 1-8, wherein each first microneedle characterized by an elevation angle of about 40° to 80° is oriented such that a first microneedle tip faces in one rotational direction, and each second microneedle characterized by an elevation angle of about 40° to 80° is oriented such that a second microneedle tip faces in a rotational direction opposite the rotational direction of the first microneedle tip.

10. The wearable medical device of any one of claims 1-9, wherein at least a portion of the plurality of first microneedles and at least a portion of the plurality of second microneedles are each independently characterized by an elevation angle of about 40° to 80° and are each independently arranged at an orientation angle of -25° to 25°.

11. The wearable medical device of any one of claims 1-10, wherein the plurality of first microneedles and the plurality of second microneedles are each independently characterized by a length of about 0.2 mm to about 3.0 mm.

12. The wearable medical device of any one of claims 1-11, wherein the first plurality of microneedles and the second plurality of microneedles are each independently characterized by a diameter of about 1 pm to about 25 pm.

13. The wearable medical device of any one of claims 1-12, wherein at least a portion of the first plurality of microneedles or at least a portion of the second plurality of microneedles is characterized by a non-uniform diameter.

14. The wearable medical device of any one of claims 1-13, wherein at least a portion of the first plurality of microneedles or at least a portion of the second plurality of microneedles is barbed.

15. The wearable medical device of any one of claims 1-14, the first plurality of microneedles arranged in at least one row, and the second plurality of microneedles arranged in at least one row.

16. The wearable medical device of any one of claims 1-15, the at least one communication member selected from a flexible rod, a flexible band, and a spring.

17. The wearable medical device of any one of claims 1-16, the at least one communication member is a rolling disc.

18. An applicator for attaching the wearable medical device of any one of claims 1-17 to a skin surface, the applicator comprising: a loading actuator configured to counter-rotationally load the first rotationally distinct segment and the second rotationally distinct segment; a retaining element to retain the wearable medical device in the counter-rotationally loaded configuration; and a mechanism for releasing the wearable medical device from the counter-rotationally loaded configuration.

19. An applicator for attaching the wearable medical device of any one of claims 1-17 to a skin surface, the applicator comprising: a driving actuator configured to rotationally rotate a first rotationally distinct segment and a second rotationally distinct segment in a counter-rotational manner.

20. A method for attaching a wearable medical device to a skin surface, the method comprising: providing the wearable medical device of any one of claims 1-17; rotating the first rotationally distinct segment and rotating the second rotationally distinct segment such that the wearable medical device is in a counter-rotationally loaded configuration; contacting the wearable medical device in the counter-rotationally loaded configuration with the skin surface; and releasing the wearable medical device from the counter-rotationally loaded configuration such that the first plurality of microneedles and the second plurality of microneedles are driven into the skin surface.

21. A method for attaching a wearable medical device to a skin surface, the method comprising: providing the wearable medical device of any one of claims 1-17; contacting the wearable medical device with the skin surface; and rotating the first rotationally distinct segment and rotating the second rotationally distinct segment such that the first plurality of microneedles and the second plurality of microneedles are driven into the skin surface. ​ ​ ​ 22. A method for attaching a wearable medical device to a skin surface, the method comprising: providing an applicator according to claim 18 having the wearable medical device therein; rotating the first rotationally distinct section and rotating the second rotationally distinct section such that the wearable medical device is in a counter-rotationally loaded configuration; contacting the wearable medical device in the counter-rotationally loaded configuration with the skin surface; and releasing the wearable medical device from the counter-rotationally loaded configuration such that the plurality of first microneedles and the plurality of second microneedles are driven into the skin surface.

23. A method for attaching a wearable medical device to a skin surface, the method comprising: providing an applicator according to claim 19 having the wearable medical device therein; contacting the applicator with the skin surface; and rotating a first rotationally distinct section and rotating a second rotationally distinct section such that a plurality of microneedles are driven into the skin surface.

24. A method for monitoring a biological signal, the method comprising: detecting a biological signal with a monitoring device secured to a wearable medical device according to any one of claims 1 to 17, the wearable medical device attached to a skin surface.

25. A kit, the kit comprising: a wearable medical device according to any one of claims 1 to 17; a set of instructions directing a user to attach the wearable medical device to a skin surface.

26. The kit of claim 25, further comprising one or more of: an applicator, and a monitoring device.

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