Vacuum tensioning applicator and method for attaching a wearable medical device to a skin surface

Abstract

A vacuum tensioning applicator and method of use are described for attaching a wearable medical device to a stretched skin surface, the wearable medical device having a plurality of microneedles on a first rotationally distinct segment and a plurality of microneedles on a second rotationally distinct segment.

Description

[Technical Field]

[0001] The industry of wearable medical and / or fitness monitoring devices is growing. People are becoming more interested in monitoring their health and remotely sharing their health data with doctors or emergency personnel. Many current devices that monitor parameters such as heart rate, blood pressure, and oxygen saturation take the form of wearable jewelry, such as watches, bracelets, rings, chest straps, and the like. However, not all parameters can be measured this way, and these wearable devices are not unobtrusive. For example, continuous glucose monitoring via devices adhered to the skin has become increasingly popular among diabetics and even those on low-carb diets. However, the adhesives required to attach such devices often cause skin damage and infections, 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 the device.

[0002] What is needed is a method of securing a monitoring device to the skin that does not require the use of adhesives. Summary of the Invention

[0003] In one embodiment, an applicator for attaching a wearable medical device to a skin surface is described. The applicator includes a loading actuator configured to counter-rotationally load first and second rotationally distinct segments of the wearable medical device, a holding system configured to hold the wearable medical device in the counter-rotationally loaded configuration, a skin tensioning system having a chamber surrounding an area in the applicator where the wearable medical device is housed and configured to contact an area on the skin surface, and a mechanism for applying reduced pressure to the area on the skin surface, and a mechanism for releasing the wearable medical device from the counter-rotationally loaded configuration.

[0004] In one embodiment, an applicator for attaching a wearable medical device to a skin surface is described. The applicator includes a drive actuator configured to rotate a first rotationally distinct segment within the wearable medical device and rotate a second rotationally distinct segment in a counter-rotational manner. The applicator further includes a skin tensioning system having a chamber surrounding an area in the applicator where the wearable medical device is housed and configured to contact an area of ​​the skin surface, and a mechanism for applying reduced pressure to the area of ​​the skin surface.

[0005] In one embodiment, a method for attaching a wearable medical device to a stretched skin surface is described. The method includes providing an applicator as described herein having a wearable medical device therein, rotating a first rotationally distinct segment and rotating a second rotationally distinct segment of the wearable medical device such that the wearable medical device is in a counter-rotationally loaded configuration. The method further includes contacting the applicator to a skin surface such that a chamber contacts the skin surface, engaging a mechanism for applying reduced pressure to the skin surface to create the stretched skin surface, and releasing the wearable medical device from the counter-rotationally loaded configuration such that a first plurality of microneedles and a second plurality of microneedles of the wearable medical device are driven into the stretched skin surface.

[0006] In many embodiments, a method for attaching a wearable medical device to a stretched skin surface is described. The method includes providing an applicator described herein having a wearable medical device therein, contacting the applicator with a skin surface such that the chamber contacts the skin surface, and engaging a mechanism for applying reduced pressure to the skin surface to create a stretched skin surface. The method further includes rotating a first rotationally distinct segment and rotating the rotationally distinct segment such that a plurality of first microneedles and a plurality of second microneedles of the wearable medical device are driven into the stretched skin surface.

[0007] In one embodiment, a kit is described that includes the applicator of the present disclosure and a set of instructions for attaching the wearable medical device to a skin surface. [Brief explanation of the drawings]

[0008] The present application may be more fully understood from consideration of the following detailed description of various embodiments of the present disclosure in connection with the accompanying drawings. [Figure 1A] FIG. 1 is a bottom side view of a wearable medical device of the present disclosure. [Figure 1B] FIG. 1B is a top view of the wearable medical device of FIG. 1A. [Figure 2A] FIG. 1 is a top side view of a wearable medical device of the present disclosure. [Figure 2B] FIG. 2B is a top view of the wearable medical device of FIG. 2A. [Figure 3A] FIG. 1 is a bottom side view of a wearable medical device of the present disclosure. [Figure 3B] FIG. 2B is a top view of the wearable medical device of FIG. 2A. [Figure 4] 1 shows a side view and elevation angle measurement of a microneedle of the present disclosure. [Figure 5] 1 shows a top view and orientation angle measurements of a microneedle of the present disclosure. [Figure 6A] FIG. 1 is a top view of a wearable medical device in an unloaded configuration with a mechanical actuator. [Figure 6B] FIG. 1 is a top view of a wearable medical device in a loaded configuration with a mechanical actuator. [Figure 7A] An applicator into which a wearable medical device is inserted. [Figure 7B] 7B is the applicator of FIG. 7A with the wearable medical device in a counter-rotationally loaded configuration. [Figure 8] FIG. 1 is a diagram of an applicator of the present disclosure tensioning a skin surface. [Figure 9] FIG. 1 is a diagram of an applicator of the present disclosure tensioning a skin surface. [Figure 10] 1 is a portion of an applicator of the present disclosure having an exemplary skin tensioning system and having a wearable medical device inserted therein. [Figure 11A] 1 is a portion of an exemplary skin tensioning system for use with the applicator of the present disclosure. [Figure 11B] 1 is an exemplary tensioning actuator for use in a skin tensioning system. [Figure 12] FIG. 1 is a side view of a portion of an exemplary applicator of the present disclosure. [Figure 13] 1 is a diagram of a portion of an applicator of the present disclosure tensioning a skin surface. [Figure 14] FIG. 1 is a diagram of an applicator of the present disclosure tensioning a skin surface.

[0009] In the following description, reference is made to the accompanying drawings. Various embodiments in which the present disclosure may be practiced are provided by way of example. It is understood that structural changes may be made without departing from the scope of the present disclosure. The drawings are not necessarily to scale. Like numbers used in the drawings refer to like components (e.g., 102, 202, 302, etc., 110, 210, 310, etc.). DETAILED DESCRIPTION OF THE INVENTION

[0010] The present disclosure describes a wearable medical device that can be secured to the skin via microneedles and an applicator for attaching the wearable medical device to the skin surface. The wearable medical device utilizes opposing forces between rotating segments to not only drive the microneedles into the skin but also secure the microneedles within the skin. Wearable medical devices that are attached to the skin via microneedles are much more resistant to accidental removal and can be worn for longer periods of time than comparable devices that are adhered to the skin via adhesives. Furthermore, the wearable medical devices of the present disclosure are painless to apply and do not cause skin damage or side effects often associated with adhesives. Additionally, the wearable medical devices of the present disclosure allow airflow underneath the device to prevent bacterial growth due to moisture accumulation and further enable cleaning.

[0011] While a wearable medical device may include a permanent monitoring device thereon, the wearable medical device of the present disclosure is primarily intended to function as a base plate for securing a removable monitoring device thereto, and users may enjoy the versatility of a modular system.

[0012] The applicators described herein provide tensioning of the skin surface to further extend the duration of wear. Attaching the wearable medical device to a stretched skin surface allows for more secure anchoring of the microneedles when the skin surface relaxes.

[0013] definition As used herein, the term "about" means plus or minus ten percent of a given value. For example, about ten means nine to eleven.

[0014] As used herein, the term "adhesive" refers to a polymeric composition that bonds two adherends together. Examples of adhesives are pressure sensitive adhesives and gel adhesives.

[0015] As used herein, the term "actuation guide" refers to a feature on or in a component of an applicator that is complementary to an applicator guide in a wearable medical device. Engagement of the actuation guide and applicator guide by a rotation means in the applicator is effective to rotate a first rotationally distinct segment and / or a second rotationally distinct segment in the wearable medical device.

[0016] As used herein, the term "applicator guide" or "applying guide" refers to a feature on or in a component of a wearable medical device that is complementary to an actuation guide in an applicator. Engagement of the applicator guide and actuation guide by a rotation means in the applicator is effective to rotate a first rotationally distinct segment and / or a second rotationally distinct segment in the wearable medical device.

[0017] As used herein, the term "barbed" describes features on the microneedle body that extend outward at an angle from the microneedle body. Barbed needles may be more difficult to remove from the skin surface than non-barbed needles. Similarly, barbed needles may prevent complete puncture compared to non-barbed needles. Barbed needles may increase adhesion, thereby increasing the duration of wear. Barbed needles may also aid in achieving a desired gap between the wearable medical device and the skin surface.

[0018] As used herein, "center" refers to the point where two perpendicular planes intersect and the areas of the four quadrants are equal. For example, the center of the microneedle base is the center of the area in contact with each of the rotationally distinct segments.

[0019] As used herein, the term "communicating member" refers to a material connecting a first rotationally different segment and a second rotationally different segment, but which does not prevent the first rotationally different segment and the second rotationally different segment from rotating independently. As used herein, the term "tensioned communicating member" refers to an article connecting a first rotationally different segment and a second rotationally different segment, where potential energy is stored within the article that deforms when the first rotationally different segment and the second rotationally different segment are rotated and 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 rotating article at least partially located between a first rotationally different segment and a second rotationally different segment, where rotating the first rotationally different segment and the second rotationally different segment causes the rotating article to rotate accordingly.

[0020] As used herein, the term "counter-rotationally" is used to describe how a first rotationally distinct segment and a second rotationally distinct segment are rotated relative to one another, with one segment rotated clockwise and the other segment rotated counterclockwise.

[0021] As used herein, "flexible" describes an article that can be stretched, bent, compressed, or otherwise twisted under the application of a force, but at least partially returns to its undistorted, undistorted, unstretched, bent, compressed, or twisted state when the force is removed.

[0022] As used herein, the term "microneedle" refers to a microstructured projection with a sharp tip configured to pierce the skin.

[0023] As used herein, "rotation" means to move some distance about an axis of rotation.

[0024] As used herein, the phrase "rotationally distinct" refers to a component that can be rotated independently of another component. For example, two rotationally distinct components that are otherwise connected can be rotated to some degree in opposite directions.

[0025] DESCRIPTION OF THE DRAWINGS 1A is a bottom view of a wearable medical device 100 of the present disclosure, illustrating a first major surface of a base 102. The wearable medical device 100 includes a base 102 having 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 rotationally distinct segment 104 and the second rotationally distinct segment 108 are shown in the shape of concentric cylindrical rings connected by a (tensioning) communicating member 112 (shown here as a flexible rod or band). The communicating member 112 is shown connecting the first rotationally distinct segment 104 and the second rotationally distinct segment 108 in a non-radial manner. During application, a loading actuator (not shown) rotates the first rotationally distinct segment 104 in a direction opposite (shown here clockwise) from the tip of the first microneedle 106 and rotates the second rotationally distinct segment 108 in a direction opposite (shown here counterclockwise) from the tip of the second microneedle 110, thereby contracting the communicating member 112. The communicating member 112 extends upon rotation of the first and second rotationally distinct segments. Alternative configurations for bending the communicating member 112 in other ways can be readily envisioned. A retaining element (not shown) holds each rotationally distinct segment 104 / 108 in a counter-rotationally loaded configuration. Upon contact with the skin, the retaining element (not shown) may be disengaged to release the wearable medical device 100, whereupon the first and second microneedles 106 / 110, which are in opposite directions, are driven into the skin surface by the communicating member 112, which at least partially returns to a relaxed (tensioned) state.

[0026] 1B is a top view of the wearable medical device 100 of FIG. 1A illustrating the second major surface of the base 102. The first rotationally distinct segment 104 and the second rotationally distinct segment 108 are shown in the shape of concentric cylindrical rings connected by a communicating member 112.

[0027] 2A is a top-side view of a wearable medical device 200 of the present disclosure, illustrating a first major surface 202a and a second major surface 202b of a base 202. The wearable medical device 200 includes a base 202 having a first rotationally distinct segment 204 having a plurality of first microneedles 206 thereon and a second rotationally distinct segment 208 having a plurality of second microneedles 210 thereon. The first rotationally distinct segment 204 and the second rotationally distinct segment 208 are shown in the shape of concentric cylindrical rings in mechanical communication by a (rolling) communicating member 212 (shown here as a rolling disk). During application, a drive actuator (not shown) rotates the first rotationally distinct segment 204 in a direction (shown here clockwise) that aligns with the tip of the first microneedle 206 and rotates the second rotationally distinct segment 208 in a direction (shown here counterclockwise) that aligns with the tip of the second microneedle 210, thereby rolling the communicating member 212. Upon contact with the skin, the drive actuator drives the first and second microneedles 206 / 210 into the skin surface.

[0028] 2B is a top view of the wearable medical device 200 of FIG. 2A illustrating the second major surface of the base 202. The first rotationally distinct segment 204 and the second rotationally distinct segment 208 are shown in the form of concentric cylindrical rings that are in mechanical communication by a (rolling) communication member 212.

[0029] 3A is a view of the bottom side of wearable medical device 300, illustrating first and second major surfaces 302a, 302b of base 302. Wearable medical device 300 includes base 302 having a first rotationally distinct segment 304 having a plurality of first microneedles 306 thereon and a second rotationally distinct segment 308 having a plurality of second microneedles 310 thereon. First and second rotationally distinct segments 304, 308 are shown in the shape of concentric cylindrical rings, with each microneedle 306 / 310 arranged in three rows. Wearable medical device 300 further includes a flexible membrane 311 in contact with second major surface 302b. A flexible membrane 311 is adhered to the first rotationally distinct segment 304 and the second rotationally distinct segment 308 and acts as a (tensioned) communicating member 312 therebetween. During application, a loading actuator (not shown) rotates the first rotationally distinct segment 304 in a direction opposite (shown here counterclockwise) from the tip of the first microneedle 306 and rotates the second rotationally distinct segment 308 in a direction opposite (shown here clockwise) from the tip of the second microneedle 310, thereby stretching the flexible membrane 311 / communicating member 312 therebetween. A holding element (not shown) holds each rotationally distinct segment 304 / 308 in a counter-rotationally loaded configuration. Upon contact with the skin, the retaining element (not shown) may disengage to release the wearable medical device 300, whereupon the opposing first and second microneedles 306 / 310 are driven into the skin surface by the flexible membrane 311 / communicating member 312 at least partially returning to a relaxed state.

[0030] 1A , depicting the second major surface of the base 302. A portion of the flexible membrane 311 / communicating member 312 can be seen between the inner positioning backing 314 covering the first rotationally distinct segment (not shown) and the outer positioning backing 316 covering the second rotationally distinct segment (not shown). The inner positioning backing 314 is shown having an inner applicator guide 318, and the outer positioning backing 316 is shown having an outer applicator guide 320. During application, a loading actuator (not shown) rotates the first rotationally distinct segment (not shown) in one direction (shown here clockwise) through communication with the inner positioning backing 314 / inner applicator guide 318 and rotates the second rotationally distinct segment (not shown) in the opposite direction (shown here counterclockwise) through communication with the outer positioning backing 316 / outer applicator guide 320. In effect, the flexible membrane 311 / communicating member 312 is stretched or otherwise twisted. Retaining elements (not shown) hold each rotationally distinct segment in a counter-rotationally loaded configuration. Upon contact with the skin, the retaining elements (not shown) may disengage to release the wearable medical device 300, whereupon the first and second microneedles (not shown) are driven into the skin surface by the flexible membrane 311 / communicating member 312 returning to at least partially unstretched.

[0031] FIG. 4 shows a side view of an exemplary first microneedle 406 (or second microneedle) of the present disclosure. 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 in a microneedle tip 426. The first microneedle 406 is angled at an elevation angle 428 ("θ"). EA"). The elevation angle 428 is measured from a plane A, which is parallel to the surface where the first microneedle 406 meets the first rotationally distinct segment 404, to the microneedle tip 426 (see plane C), relative to a plane B that passes through the center of the microneedle base 422, where planes A and B are perpendicular to each other, i.e., 90°.

[0032] 5 shows a top view of a first rotationally distinct segment 504 having a plurality of first microneedles 506 disposed thereon (or a second rotationally distinct segment having a second microneedle disposed thereon) of the present disclosure. Each of the plurality of first microneedles 506 independently has an orientation angle 530 ("θ OA "). The orientation angle 530 is measured relative to radial plane D and tangential plane E (i.e., tangential plane E is tangent to radial plane D, i.e., 90°). Plane F is parallel to plane E and is merely for visual aid purposes. Each radial plane D passes through the center of the microneedle base 522 (see plane B in FIG. 4, i.e., radial plane D is in the z direction perpendicular to plane B, and tangential planes E and A are in the x direction). The first microneedle 506a aligned with tangential planes E and F has an orientation angle 530 of 0°, i.e., θ OA = 0°. The first microneedle 506b, angled towards the axis of rotation, has an orientation angle 530 that is less than 0° by some measurable amount, i.e., θ OA <0°, e.g., −10°. The first microneedle 506c angled away from the axis of rotation has an orientation angle 530 greater than 0° by some measurable degree, i.e., θ OA >0°, for example 10°. The description need not be limited to circular structures.

[0033] 6A shows a top view (second major surface) of a wearable medical device 600 having a pair of mechanical actuators 632a / 632b, with the medical device shown in an unloaded configuration. The wearable medical device 600 includes a base 602 having a first rotationally distinct segment 604, a second rotationally distinct segment 608, and a communication member 612. The first mechanical actuator 632a is in communication with the first rotationally distinct segment 604, and the second mechanical actuator 632b is in communication with the second rotationally distinct segment 608. When the mechanical actuators 632a / 632b are squeezed together, the first rotationally distinct segment 604 rotates counterclockwise and the second rotationally distinct segment 608 rotates clockwise. The mechanical actuators 632a / 632b can be used to attach or detach the wearable medical device to or from the skin surface.

[0034] 6B shows a top view of a wearable medical device 600 with a pair of mechanical actuators 632a / 632b, where the medical device is shown in a loaded configuration and the communicating member 612 is shown elongated compared to the unloaded configuration of FIG.

[0035] 7A shows an exemplary applicator 701 with a wearable medical device 700 inserted in an unloaded configuration. The applicator 701 does not include a skin tensioning system as described in this disclosure. The applicator 701 is shown to illustrate aspects of the applicator related to loading a wearable medical device. The applicator 701 is shown to include a first segment actuation guide 703 within an inner wall 705 that mates with a first applicator guide 707 located on a first rotationally distinct segment 704. The applicator 701 is further shown to include a second segment actuation guide 709 within an outer wall 711 that mates with a second applicator guide 713 located on a second rotationally distinct segment 708.

[0036] 7B shows an exemplary applicator 701 with the wearable medical device 700 in a counter-rotationally loaded configuration. The first rotationally distinct segment 704 is rotated clockwise and the second rotationally distinct segment 708 is rotated counter-clockwise. The applicator 701 holds the wearable medical device 700 in this counter-rotationally loaded configuration (retaining element not shown) until the applicator 701 contacts a skin surface. Disengaging the retaining element (not shown) releases the wearable medical device 700 from the loaded configuration and drives multiple microneedles on each segment into the skin surface.

[0037] 8 shows a cross-sectional view of an applicator 801 of the present disclosure, where a skin tensioning system 813 has a chamber 835 located outside / external to an applicator body 837, and the applicator 801 is used to tension the skin surface SS to create a stretched skin surface TSS. The applicator 801 is pressed against the skin surface SS so that the chamber 835 contacts the skin surface SS. A mechanism for applying reduced pressure within the chamber 835, such as a syringe 839, is engaged to reduce the pressure within the chamber 835 and create a stretched skin surface TSS. A wearable medical device 800 of the present disclosure is shown housed within the confines of the chamber 835. The wearable medical device 800 (shown with a first microneedle 806 and a second microneedle 810) is either (1) released from a counter-rotationally loaded configuration into the stretched skin surface TSS, or (2) driven into the stretched skin surface TSS via a drive actuator (not shown). Although not shown, a docking platform may extend the wearable medical device 800 from the applicator body so that the wearable medical device 800 contacts the stretched skin surface TSS.

[0038] 9 illustrates a cross-sectional view of an applicator 901 of the present disclosure, where the skin tensioning system 913 has a chamber 935 located inside / within an applicator body 937, and the applicator 901 is used to tension the skin surface SS to create a stretched skin surface TSS. The applicator 901 is pressed against the skin surface SS so that the chamber 935 contacts the skin surface SS. A mechanism for applying reduced pressure within the chamber 935, such as a syringe 939, is engaged to reduce the pressure within the chamber 935 and create a stretched skin surface TSS. A wearable medical device 900 of the present disclosure is shown housed within the confines of the chamber 935. The wearable medical device 900 (shown with a first microneedle 906 and a second microneedle 910) is either (1) released from a counter-rotationally loaded configuration into the stretched skin surface TSS, or (2) driven into the stretched skin surface TSS via a drive actuator (not shown). Although not shown, a docking platform may extend the wearable medical device 900 from the applicator body so that the wearable medical device 900 contacts the stretched skin surface TSS.

[0039] 10 shows a portion of an applicator 1001 of the present disclosure in which a portion of an exemplary skin tensioning system 1013b having a plurality of tensioning needles 1017 / 1021 surrounds the area where the wearable medical device 1000 is located. The portion of the skin tensioning system having a chamber is not shown. The applicator 1001 is shown to include a skin tensioning system 1013b having a first rotationally different tensioning segment 1015 having a plurality of first tensioning microneedles 1017 thereon and a second rotationally different tensioning segment 1019 having a plurality of second tensioning microneedles 1021 thereon. The first rotationally different tensioning segment 1015 and the second rotationally different tensioning segment 1019 are configured to operate similarly to the wearable medical device 1000, although there is no communicating member.

[0040] 11A shows a portion of an exemplary skin tensioning system 1113b for use in an applicator of the present disclosure. The skin tensioning system 1113b is shown to include a first rotationally different tensioning segment 1115 having a plurality of first tensioning microneedles 1117 thereon and a second rotationally different tensioning segment 1119 having a plurality of second tensioning microneedles 1121 thereon. The skin tensioning system 1113b is further shown to include a tensioning actuator 1123 configured to rotate the first rotationally different tensioning segment 1115 and the second rotationally different tensioning segment 1119.

[0041] Figure 11B shows the tensioning actuator 1123 of Figure 11A without the tensioning segments. The tensioning actuator 1123 includes a ring gear 1125 configured to rotate a first rotationally distinct tensioning segment (not shown), a sun gear 1127 configured to rotate a second rotationally distinct tensioning segment (not shown), and a planetary gear 1129 positioned therebetween.

[0042] 12 shows a side view of a portion of an applicator 1201 of the present disclosure, having an applicator housing 1231 and a torsion drive shaft 1233. The tensioning drive shaft 1233 is one element of a skin tensioning system and is configured to drive a tensioning actuator 1223. The applicator 1201 is further shown to include a plurality of first tensioning microneedles 1219 and a plurality of second tensioning microneedles 1221.

[0043] 13 illustrates a cross-sectional view of a portion of an applicator 1301 of the present disclosure tensioning a skin surface SS. The applicator 1301 is pressed against the skin surface SS, applying a force F applied from a first tensioning microneedle 1317 and a second tensioning microneedle 1321. A However, the skin surface SS exerts an opposing force F O The tensioning drive shaft 1333 is twisted to rotate a first rotationally different tensioning segment (not shown) having a first tensioning microneedle 1317 thereon and rotate a second rotationally different tensioning segment (not shown) having a second tensioning microneedle 1321 thereon, thereby tensioning the skin surface area between the tensioning microneedles to form a stretched skin surface TSS. The stretched skin surface TSS is maintained in this stretched state while the wearable medical device 1300 is released from the counter-rotationally loaded configuration such that the first microneedle 1306 and the second microneedle 1310 are driven into the stretched skin surface TSS.

[0044] 14 shows a cross-sectional view of an applicator 1401 of the present disclosure having a skin tensioning system 1413 including (1) a chamber 1435, a mechanism (not shown) for reducing pressure within the chamber 1435, and (2) a plurality of tensioning microneedles 1417 and a tensioning actuator (not shown), where the chamber 1435 and the tensioning microneedles 1417 are arranged around an area within the applicator 1401 that houses a wearable medical device 1400 (having a first microneedle 1406 and a second microneedle 1410). The wearable medical device 1400 is either (1) released from a counter-rotationally loaded configuration into the stretched skin surface TSS, or (2) driven into the stretched skin surface TSS via a drive actuator (not shown). Although not shown, a docking platform may extend the wearable medical device 1400 from the applicator body so that the wearable medical device 1400 contacts the stretched skin surface TSS.

[0045] Wearable Medical Devices In various embodiments, a wearable medical device is described. The wearable medical device may include a base having a first rotationally distinct segment and a second rotationally distinct segment. The second rotationally distinct segment may at least partially surround the first rotationally distinct segment. At least one communication member may be in communication with the first rotationally distinct segment and the second rotationally distinct segment. The wearable medical device may further include 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.

[0046] Further details and features of the wearable medical device are described below, and it should be understood that the details and features described below may be incorporated alone or in any combination, unless otherwise stated.

[0047] base The base, and all components within the base, may be characterized by a first major surface and a second major surface. The first major surface is considered to be the skin-contacting 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 and second microneedles described herein are located on the first major surface of the base.

[0048] In some embodiments, the base may further include one or more applicator guides for mating with the applicator, the applicator guides configured to rotate the first rotationally distinct segment and the second rotationally distinct segment. For example, the applicator guides may be in the form of one or more notches, protrusions, pins, pinholes, etc., and may be complementary to actuation guides in the applicator. The applicator guides may be located on the second major surface, along the periphery (minor surface), or a combination thereof.

[0049] In some embodiments, the base may further include one or more monitoring device securement features for attaching the monitoring device to a wearable medical device. Exemplary monitoring device securement features may include clips, hooks, latches, brackets, threaded components for mating with threaded monitoring devices, adhesives, or combinations thereof. The monitoring device securement features may be located on the second major surface, along the periphery (minor surface), or combinations thereof.

[0050] In some embodiments, the base may 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. Figures 6A and 6B illustrate exemplary mechanical actuation of an applicator-free wearable medical device described herein. While Figures 6A and 6B illustrate counter-rotational loading of the wearable medical device (i.e., pushing the mechanical actuators together), the reverse is also contemplated. For example, a wearable medical device having a rolling communicating member (e.g., Figure 2A) may include a mechanical actuator that can be used to drive multiple microneedles into the skin surface (i.e., pushing the mechanical actuators apart).

[0051] In some embodiments, a mechanical actuator may be used to apply and / or remove a wearable medical device from a skin surface, with or without an applicator described herein. A mechanical actuator is not required to use the applicators described herein, but the applicator may be configured to actuate the mechanical actuator. In other words, any such mechanical actuator, when combined with an applicator, may be considered an "applicator guide" as used herein.

[0052] In some embodiments, the base may further include a flexible membrane that is adhered to or otherwise connected to the second major surface and extends from at least a first rotationally distinct segment to a second rotationally distinct segment such that the first rotationally distinct segment may be in communication with the second rotationally distinct segment (i.e., is a communicating member). In some embodiments, the flexible membrane may span the entire second major surface of the base. In some embodiments, the flexible membrane may extend beyond the periphery of the base. A base having a flexible membrane that extends beyond the periphery of the base may further include an adhesive thereon that may function as a secondary skin attachment feature.

[0053] In some embodiments, the flexible membrane may be constructed from materials such as woven fabric (e.g., cotton, rayon, polyvinyl chloride, polyethylene, or polyurethane), latex, etc. In some embodiments, the flexible membrane may be breathable and waterproof.

[0054] In some embodiments, the flexible membrane may further include an adhesive on one or more surfaces. In some embodiments, suitable adhesives may be comprised of acrylates, methacrylates, epoxy diacrylates, etc. The adhesive may be located on the surface that contacts the skin surface upon application and thus serve as a secondary means for securing the wearable medical device to the skin. The adhesive may also be located on the surface opposite the skin surface upon application and serve as a placement backing and / or a means for attaching the monitoring device (i.e., a monitoring device securement feature). In some embodiments, the flexible membrane may be in the form of double-sided tape.

[0055] In many embodiments, the flexible membrane may be optically transparent. In many embodiments, the flexible membrane may be constructed from a material that is easily pierceable (e.g., by a needle). In other embodiments, the flexible membrane may include areas free of material for passage of a needle (e.g., a needle extending from an attached glucose monitoring device), light (e.g., transmitted from an attached oximeter device), an electrode, or some other skin-contacting or piercing probe.

[0056] In many embodiments, the base may further include a flexible membrane as described herein and one or more positioning backings. The one or more positioning backings may be reversibly or irreversibly adhered to the flexible membrane using an adhesive or may otherwise be sewn onto the flexible membrane. The positioning backing may include an application guide configured to mate with a loading actuator in the applicator. In some embodiments, the positioning backing may include an inner positioning backing configured to rotate a first rotationally distinct segment (e.g., by an inner application guide) and an outer positioning backing at least partially surrounding the inner positioning backing and configured to rotate a second rotationally distinct segment (e.g., by an outer application guide).

[0057] Rotationally distinct segments In many embodiments, the first and second rotationally distinct segments may be arranged to share a common axis of rotation. While separate axes of rotation are envisioned and intended to be within the scope of the present disclosure, a shared axis of rotation is the simplest and most elegant configuration.

[0058] In many embodiments, the first and second rotationally distinct segments are configured to rotate in opposite directions (i.e., clockwise and counterclockwise relative to one another), and the rotation induces stress within the communicating member communicating with each. The stress may be in the form of elongation, compression, twisting, bending, coiling, rolling, rotation, etc. The applicator of the present disclosure, or other applicator means, may be configured to fix the first and second rotationally distinct segments in a rotational state and withstand potential energy within the stressed communicating member. The kinetic energy provided by the release of stress within the communicating member is effective to unrotate the rotational distinct segments, allowing the microneedles thereon to be driven into the skin with some force.

[0059] The first and second rotationally distinct segments may independently be any size and shape, so long as neither segment impedes the rotation of the other. Exemplary shapes include cylindrical or semi-cylindrical, elliptical cylindrical, truncated conical, rectangular, square, truncated conical, etc., and the shapes may be either solid or annular (i.e., ring-like). An annular first rotationally distinct segment may allow transmission of light from an attached monitoring device or otherwise allow physical contact between the skin surface and the attached monitoring device. In some embodiments, the first and second rotationally distinct segments may each be cylindrical rings (i.e., washer-like) and may be concentrically arranged. In other embodiments, the first rotationally distinct segment may be a solid cylinder, and the second rotationally distinct segment may be concentrically arranged cylindrical rings. Some shapes may be better suited for different applications, such as to accommodate different regions of the body or to accommodate monitoring devices of different shapes.

[0060] In many embodiments, the first and second rotationally distinct segments are arranged such that at least one major surface of each of the segments is coplanar with one another. In any embodiment in which the first and second rotationally distinct segments are not such that at least one major surface of each of the segments is coplanar with one another, the wearable medical device will require the first and second microneedles to be unequal in length so that each set of microneedles can contact the skin.

[0061] In some embodiments, the first and second rotationally distinct segments may be independently characterized by a maximum length and a maximum width of about 5 mm to about 75 mm. For example, the maximum length and / or width may be selected from about 5, 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, or 75 mm, or may be within a range between any of the foregoing values, such as, for example, from about 25 to about 40 mm.

[0062] In some embodiments, the first and second rotationally distinct segments may be independently characterized by an average thickness of about 1 mm to about 10 mm. For example, the average thickness may be selected from 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 mm, or may be a value within a range between any of the foregoing values, such as, for example, from about 3 to about 8 mm.

[0063] In many embodiments, the first and second rotationally distinct segments may each include at least 10 microneedles thereon. In some embodiments, the first and second rotationally distinct segments may each, independently, include between 10 and 500 microneedles thereon. For example, the first and second rotationally distinct segments may each, independently, include 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 microneedles, or any number within a range between any of the foregoing values, such as between about 50 and about 100. The number of needles in each of the rotationally distinct segments may be selected according to various factors, such as intended device placement, skin type, user activity level, intended duration of wear, etc.

[0064] In some embodiments, the first rotationally distinct segment may include one or more first applicator guides configured to mate with one or more actuator guides in an applicator described herein. The one or more first applicator guides may be located on an inner periphery (minor surface) of the first rotationally distinct segment. In some embodiments, the second rotationally distinct segment may include one or more second applicator guides configured to mate with one or more actuator guides in an applicator described herein. The one or more second applicator guides may be located on an outer periphery (minor surface) of the second rotationally distinct segment. In some embodiments, the first and second applicator guides may independently be in the form of a notch, protrusion, pin, pinhole, or the like.

[0065] In some embodiments, the first and second rotationally distinct segments may be constructed from a material selected from metal, plastic, or a combination thereof.

[0066] In some embodiments, a wearable medical device may have only two rotationally distinct segments, hi other embodiments, a wearable medical device may have more than two rotationally distinct segments, and any additional rotationally distinct segments may be characterized similarly to any of the rotationally distinct segments described herein.

[0067] (Connecting member) In some embodiments, the communication member may be a tensioned communication member selected from a flexible rod or band, a spring, a flexible membrane (described above), combinations thereof, etc. In other embodiments, the communication member may be a rolling communication member, such as a rolling disk.

[0068] In some embodiments, the communication member may be in the form of a flexible rod, a flexible band, or a spring.

[0069] In many embodiments, the communicating member may at least partially connect the first rotationally distinct segment and the second rotationally distinct segment via a minor surface (e.g., an inner or outer wall between ring-shaped rotationally distinct segments). In some embodiments, the communicating member may 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 the first major surface having the microneedles).

[0070] In some embodiments, the wearable medical device may include one or more communication members in the form of flexible rods or bands extending from an outer wall of a first rotationally distinct segment that is ring-shaped and an inner wall of a second rotationally distinct segment that is ring-shaped. In some embodiments, the flexible rods or bands may extend radially (i.e., parallel to the radius) between the first rotationally distinct segment and the second rotationally distinct segment. In other embodiments, the flexible rods or bands may extend non-radially (e.g., at an angle relative to the radial plane) between the first rotationally distinct segment and the second rotationally distinct segment. Non-radial orientation may be measured according to one end of the communication member being on a radial plane and the other end of the communication measured at an angle of about 1° to 45° relative to the radial plane, 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., a range between about 20 and about 40. Non-radially positioned flexible rods or bands may be positioned in one of two orientations, i.e., / or \, and depending on the direction of rotation between the rotationally distinct segments, the flexible rods or bands may be stretched or bent.

[0071] In some embodiments, the type and number of communicating members present in a wearable medical device of the present disclosure may be selected according to the desired kinetic energy for driving the rotationally distinct segments together. For example, a wearable medical device may be tailored to the type of skin surface to which it will be applied, which may require a greater or lesser force to properly or safely attach the wearable medical device to the skin surface.

[0072] In some embodiments, the wearable medical device may include between 1 and 20 communicating members, such as 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 12, 15, 18, or 20 communicating members, or a range between any of the foregoing values, such as a value in the range of 2 to 6. In some embodiments, each of the communicating members is the same type. In other embodiments, there may be a mix of communicating members within the wearable medical device.

[0073] Microneedles In many embodiments, the first and second microneedles may be arranged in a circular or semicircular array extending about the axis of rotation, regardless of the shape of the first and second rotationally distinct segments. In many embodiments, the first plurality of microneedles may be arranged in one or more rows along the first rotationally distinct segment. Similarly, the second plurality of microneedles may be arranged in one or more rows along a second rotationally distinct segment within the circular path. In some embodiments, the rows may be coplanar with adjacent rows or may be staggered. In some embodiments, each of the first and second plurality of microneedles may be arranged in 1 to 5 rows, e.g., 1, 2, 3, 4, or 5 rows, e.g., 2 to 3 rows.

[0074] In some embodiments, the plurality of first and second microneedles may be arranged in an array, and each of the microneedles may independently be separated from one another by a distance of about 1 mm to about 10 mm. For example, any of the microneedles may 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 mm, or a range between any of the foregoing values, such as about 4 to about 6 mm.

[0075] In embodiments having two or more rows, the rows may be independently separated by a distance of about 5 mm to about 10 mm, for example, the rows may be independently separated by a distance of about 5.5, 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, or 10 mm, or a range between any of the foregoing values, such as from about 6 to about 8 mm.

[0076] In some embodiments, each of the first and second microneedles may be independently characterized by an elevation angle of about 40° to about 80° relative to the plane to which the microneedles are attached (i.e., each rotationally distinct segment). For example, the first and second microneedles may be independently 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 range between any of the foregoing values, such as about 45 to about 50°. For reference, a microneedle perpendicular to a parallel plane passing through each rotationally distinct segment is characterized by an elevation angle of 90°. While elevation angles outside the above ranges are still within the scope of the present disclosure, it is believed that the above ranges may provide benefits to the user in terms of pain relief, skin health, and longer wear periods. Of course, any elevation angle can be measured as an acute or obtuse angle depending on the reference point. Thus, the above-mentioned elevation angles can each be considered an obtuse angle (i.e., from about 140° to about 100°, respectively, and all angles therebetween). The elevation angles are measured from a parallel plane passing through each rotationally distinct segment to the center of the microneedle tip, relative to a plane passing through the center of the microneedle base and perpendicular to the parallel plane.

[0077] In many embodiments, each of the first microneedles may be characterized by the same elevation angle. In other embodiments, at least a portion of the first microneedles may be characterized by one elevation angle and at least another portion of the first microneedles may be characterized by another elevation angle. In some cases, a mix of elevation angles may be beneficial for tailoring the wearable medical device to the region of the body to which it is intended to be worn. In many embodiments, each of the second microneedles may be characterized by the same elevation angle. Similarly, in other embodiments, at least a portion of the second microneedles may be characterized by one elevation angle and at least another portion of the second microneedles may be characterized by another elevation angle. In some embodiments, each of the first and second microneedles may be characterized by the same elevation angle, or portions of either the first or second microneedles may be characterized by different elevation angles.

[0078] In embodiments where at least some of the first microneedles are characterized by an elevation angle other than 90°, the first microneedles at the elevation angle must all point in the same rotational direction (i.e., all tips must point clockwise or counterclockwise). Similarly, in embodiments where at least some of the second microneedles are characterized by an elevation angle other than 90°, the second microneedles at the elevation angle must all point in the same rotational direction. Furthermore, in embodiments having both first and second microneedles characterized by an elevation angle ≠ 90°, the first microneedles at the elevation angle may be oriented in the opposite rotational direction relative to the second microneedles at the elevation angle. In other words, each first microneedle characterized by an elevation angle ≠ 90° (e.g., 40° to 80°) may be oriented so that its first microneedle tip points in one rotational direction, and each second microneedle characterized by an elevation angle ≠ 90° (e.g., 40° to 80°) may be oriented so that its second microneedle tip points in the opposite rotational direction to the first microneedle tip. When pointing in opposite rotational directions, it is implied that they share a common axis of rotation.

[0079] In some embodiments, each of the first and second microneedles characterized by an elevation angle ≠ 90° may be independently positioned at an orientation angle relative to the tangent of the rotation vector (i.e., with respect to the rotation of each rotationally distinct segment) of about -25° to about 0° (aligned with the tangent) or about 0° (aligned with the tangent) to about 25°. Negative orientation angle values ​​indicate that the needle points toward the axis of rotation, while positive orientation angle values ​​indicate that the needle points away from the axis of rotation. For example, any given microneedle may be characterized by an orientation angle (°) 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 values ​​within a range between any of the aforementioned values ​​on either side of 0, e.g., about -15 to about -8, about 5 to about 12, etc. In many embodiments, each of the first and second microneedles may be positioned such that the entire needle body is aligned tangentially with the vector of rotation (i.e., an orientation angle of 0°) relative to the rotation of each rotationally distinct segment. The orientation angle is measured from a tangent plane passing through the center of the microneedle base to the center of the microneedle tip. In other words, a microneedle that is parallel to the tangent to the rotation vector is characterized by an orientation angle of 0°. Further, for reference, a microneedle characterized by an orientation angle of 90° is perpendicular to the rotation vector and will never be able to pierce the skin surface during operation of the wearable medical device.

[0080] In some embodiments, each of the first and second microneedles may be independently characterized by a length of about 0.2 mm to about 3.0 mm. For example, each of the first and second microneedles may be independently 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 mm, or a range between any of the foregoing values, such as about 0.5 to about 0.8 mm. The length of the needles may be selected based on the needs of the application. For example, shorter needles may be more comfortable for older users or in areas where the skin may be thinner.

[0081] In some embodiments, each of the first and second microneedles may be independently characterized by a diameter of about 1 μm to about 25 μm. For example, each of the first and second microneedles may be independently characterized by a diameter of about 1, 2, 5, 8, 10, 12, 15, 18, 20, 22, or 25 μm, or a value within a range between any of the aforementioned values, such as about 8 to about 12. In some embodiments, any microneedle described herein may have a uniform diameter or a non-uniform diameter within the above range. A non-uniform diameter may be characterized by a diameter that decreases along the microneedle body toward the tip. For example, a non-uniform diameter may decrease in diameter along the microneedle body toward the tip by about 5 to 25%, such as 5, 8, 10, 12, 15, 18, 20, 22, or 25%, or a value within a range between any of the aforementioned values, such as 10 to about 15. The non-uniform diameter may also include regions within the microneedle body that may be larger in diameter, or otherwise isolated regions that may be larger in diameter. Such larger diameter regions may be in the form of barbs. Microneedles with barbs may function to better anchor the microneedle within the skin surface. The larger diameter regions may also prevent the entire microneedle from piercing the skin, effectively leaving a region between the skin surface and the base that allows airflow therebetween and prevents moisture accumulation and / or bacterial growth. In some embodiments, at least a portion of the first and / or second microneedles may be characterized by a non-uniform diameter.

[0082] In many embodiments, it is desirable to leave a space between the skin surface and the wearable medical device to allow airflow to prevent moisture buildup and bacterial growth. One way to achieve this is to select microneedles of a certain length and / or a certain diameter. In other words, the microneedles need only be inserted into the skin to a certain extent. For example, the microneedles may be inserted into the skin only 25-75% of their length, e.g., 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, or 75% of their length, or any range between any of the aforementioned values. In some embodiments, the wearable medical device may be seated above the skin surface with a gap thickness of about 0.15 mm to about 1 mm, for example, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.60, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, or 1 mm, or a value within a range between any of the aforementioned values.

[0083] In some embodiments, any microneedle described herein may further include a microneedle base. The microneedle base may be any shape, but is typically at least 25% larger than the diameter of the microneedle. The microneedle base may not only provide stability, but also function to prevent the microneedle from being 100% inserted into the skin surface, thus leaving a desired gap between the skin surface and the wearable medical device. In some embodiments, the microneedle base may be frustum or truncated cone shaped.

[0084] In many embodiments, any microneedle described herein may be constructed from plastic, metal, absorbable material, or a combination thereof. Suitable plastics include polyolefin materials, polyester, polyurethane, etc. Suitable metals include stainless steel, titanium, and nitinol (nickel / titanium alloy). Absorbable materials include materials used to form absorbable sutures, such as polyglycolide (e.g., DEXON™), poly(glycolide / lactide) random copolymers (e.g., VICRYL™), etc.

[0085] In some embodiments, any of the microneedles described herein may be coated with one or more conductive materials such that the wearable medical device may function as a dry electrode.

[0086] In some embodiments, any of the microneedles described herein may be solid or hollow. Hollow microneedles may allow for the passage of therapeutic agents.

[0087] In some embodiments, each of the first and second microneedles may be the same, while in other embodiments, any one of the first microneedles or any one of the second microneedles may differ from each other in one or more aspects described above.

[0088] Applicator In many embodiments, an applicator for attaching a wearable medical device of the present disclosure to a skin surface is described. The applicator may include a loading actuator configured to counter-rotationally load first and second rotationally distinct segments of the wearable medical device, a holding system configured to hold the wearable medical device in the counter-rotationally loaded configuration, a skin tensioning system having a chamber surrounding an area in the applicator where the wearable medical device is housed and configured to contact an area on the skin surface, and a mechanism for applying reduced pressure to the area on the skin surface, and a mechanism for releasing the wearable medical device from the counter-rotationally loaded configuration. For example, an applicator having a loading actuator may be suitable for a wearable medical device described herein having a tensioning communication member.

[0089] In many embodiments, an applicator for attaching a wearable medical device of the present disclosure to a skin surface is described. The applicator may include a drive actuator configured to counter-rotate a first rotationally distinct segment and a second rotationally distinct segment within the wearable medical device, and a skin tensioning system having a chamber surrounding an area in the applicator where the wearable medical device is housed and configured to contact an area on the skin surface, and a mechanism for applying reduced pressure to the area on the skin surface. For example, an applicator having a drive actuator may be suitable for a wearable medical device described herein that has a rolling communication member.

[0090] In some embodiments, any skin tensioning system may further include a plurality of tensioning needles and a tensioning actuator configured to rotate the plurality of tensioning needles around the area in which the wearable medical device is housed within the applicator.

[0091] In some embodiments, the described applicator features may be strictly mechanically driven, while in other embodiments, the applicator features may be at least partially electrically driven.

[0092] While the applicators described herein are intended to assist in the attachment of the wearable medical devices of the present disclosure, the applicators may also be useful for attaching wearable medical devices that may deviate from the described scope, so long as the wearable medical device includes a first rotationally distinct segment, a second rotationally distinct segment, and a plurality of microneedles.

[0093] In some embodiments, the described applicator may be further configured to remove the wearable medical device from the skin surface. To remove the wearable medical device, the applicator may be brought into contact with the wearable medical device and the loading actuator may be operatively engaged to rotate the first and second rotationally distinct segments such that the first and second microneedles are removed from the skin surface.

[0094] Further details of the applicator are described below.

[0095] Loading Actuator In some embodiments, the loading actuator may include any combination of mechanical components for effecting rotation of the first and second rotationally distinct segments. For example, the loading actuator may include one or more of a spring, a gear, a piston, a pump, etc. In some embodiments, the loading actuator may include an epicycle gear system having a ring gear, a sun gear, and one or more planetary gears. For example, the ring gear may be effective to rotate the second rotationally distinct segment of the wearable medical device, and the sun gear may be effective to rotate the first rotationally distinct segment. In other words, the rotationally distinct segments of the wearable medical device may have complementary gear teeth on their respective gears. In some embodiments, the applicator may include a mechanism for engaging the loading actuator. For example, the mechanism may include twisting the applicator, retracting a plunger, etc.

[0096] In some embodiments, the loading actuator can be tailored to a particular tensioning communicating member or several communicating members. For example, the loading actuator can be configured to counter-rotationally load the wearable medical device a selected degree of rotation so that the communicating member is fully or partially unstretched once the wearable medical device is attached to the skin surface. A communicating member that is not fully unstretched after the wearable medical device is attached to the skin surface can function to further secure the wearable medical device within the skin surface, as residual stretch continues to pull the opposing microneedles into the skin. However, excessive residual stretch in the communicating member while within the skin surface can result in damage. Conversely, it is also possible to overstretch the communicating member during application. In other words, a communicating member that is unstretched past its original configuration can effectively be re-stretched. If the communicating member is overstretched while the wearable medical device is attached to the skin surface, the forces favoring its return to its original configuration may ultimately cause the communicating member to pull the microneedles from the skin surface, thereby shortening the wearing period.

[0097] Drive Actuator In some embodiments, the drive actuator may include any combination of mechanical components for effecting rotation of the first and second rotationally distinct segments. For example, the drive actuator may include one or more of a spring, a gear (e.g., an epicycle gear system), a piston, a pump, etc. In some embodiments, the applicator may include a mechanism for engaging the drive actuator. For example, the mechanism may include twisting the applicator, retracting a plunger, etc.

[0098] Retention System In some embodiments, the retention system can include any combination of mechanical components for holding the first and second rotationally distinct segments of the wearable medical device in a counter-rotationally loaded configuration, hi some embodiments, the retention system can include retention elements such as pins, latches, brackets, etc.

[0099] In some embodiments, the holding system may further include a docking platform for holding the wearable medical device within the applicator. In some embodiments, the docking platform may be extendable beyond the periphery of the applicator. For example, when tensioning the skin surface, it may be undesirable to have multiple microneedles of the wearable medical device contact the skin surface during tensioning. Thus, the docking platform may be configured to retract the wearable medical device away from the skin surface before tensioning and / or extend the wearable medical device toward the skin surface after tensioning.

[0100] Skin tension application system In some embodiments, the chamber may be contained within the applicator body / housing. For example, only the portion of the chamber intended to contact the skin surface may be visible. In other embodiments, the chamber may extend from the applicator body / housing.

[0101] In some embodiments, the chamber may be independently characterized by a length and width of about 10 mm to about 100 mm. For example, the chamber may be characterized by a length and width, in mm, selected from 10, 15, 20, 25, 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, 95, or 100, or a range between any of the aforementioned values, such as about 50 to about 80. The shape of the chamber may be any shape. For example, the surface of the chamber that contacts the skin surface may be circular, oval, or the like. The size of the chamber may be selected according to the desired level of stretch, the size of the wearable medical device to be attached, or a combination thereof.

[0102] In some embodiments, the chamber has an area within the chamber boundaries of about 75 mm 2 ~approx. 8000mm 2 For example, the area within the boundaries of the chamber may be configured to contact the skin surface such that 2 In units of about 75, 100, 125, 150, 175, 200, 225, 250, 275, 300, 325, 350, 375, 400, 425, 450, 475, 500, 600, 700, 800, 900, 1000, 1500, 2000, 2500, 3000, 4000, 4500, 5000, 6000, 7000, or 8000, or may be a value within a range between any of the foregoing values, such as from about 200 to about 350.

[0103] In some embodiments, the mechanism for reducing the pressure within the chamber in contact with the skin surface may include an electric vacuum pump, a mechanical vacuum pump, a suction valve, a syringe, or a combination thereof.

[0104] In some embodiments, the skin tensioning system may further include a plurality of tensioning microneedles and a tensioning actuator configured to rotate the plurality of tensioning microneedles around the area where the wearable medical device is housed within the applicator. Further details regarding the tensioning microneedles and tensioning actuator are provided below.

[0105] Skin tension actuator In many embodiments, the tensioning actuator can be configured to rotate the plurality of tensioned microneedles around a region (e.g., a holding system, e.g., a docking platform) in which the wearable medical device is housed within the applicator. In some embodiments, the tensioning actuator can include an epicycle gear system for rotating the plurality of microneedles around the holding system.

[0106] In some embodiments, the tensioning actuator may be configured to rotate a first plurality of microneedles in one rotational direction and a second plurality of microneedles in an opposite rotational direction (i.e., counter-rotation).

[0107] Tensioned microneedles In many embodiments, the plurality of tensioning microneedles may be present as a first plurality of tensioning microneedles and a second plurality of tensioning microneedles. In some embodiments, the first plurality of tensioning microneedles may be mounted on a first rotationally distinct tensioning segment, and the second plurality of tensioning microneedles may be mounted on a second rotationally distinct tensioning segment, with the second rotationally distinct tensioning segment at least partially surrounding the first rotationally distinct tensioning segment. The first and second rotationally distinct tensioning segments may be configured to rotate in opposite directions (i.e., counter-rotating) about the axis of rotation. In many embodiments, the first rotationally distinct tensioning segment and the second rotationally distinct tensioning segment are each in the shape of a cylindrical ring and are arranged concentrically.

[0108] In embodiments having a first rotationally different tensioning segment and a second rotationally different tensioning segment, the tensioning actuator may include an epicycle gear system having a ring gear, a sun gear, and one or more planetary gears. For example, the ring gear may be effective to rotate the second rotationally different tensioning segment, and the sun gear may be effective to rotate the first rotationally different tensioning segment. In other words, the rotationally different tensioning segments may have complementary gear teeth on their respective gears.

[0109] In some embodiments, the plurality of tensioning microneedles may be independently characterized by an elevation angle of about 40° to about 80° relative to the plane to which the microneedles are attached (e.g., each rotationally distinct tensioning segment). For example, at least some of the plurality of tensioning microneedles may be independently 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 range between any of the foregoing values, such as about 45 to about 50°. Elevation angles outside the above ranges (e.g., 90°) are still within the scope of the present disclosure but may not be sufficient to tension the skin surface. Measuring the elevation angle of the tensioning microneedles is the same as measuring the elevation angle of the microneedles on the wearable medical device described above. In embodiments having a first plurality of tensioning microneedles and a second plurality of tensioning microneedles on respective rotationally distinct tensioning segments, at least a portion of the first and second plurality of tensioning microneedles may be characterized by an elevation angle (e.g., 40-80°), and the first plurality of tensioning microneedles may be oriented such that the first tensioning microneedle tips face in one rotational direction, and the second plurality of tensioning microneedles may be oriented such that the second microneedle tips face in an opposite rotational direction to the rotational direction of the first tensioning microneedle tips.

[0110] In some embodiments, each of the first and second tensioning microneedles characterized by an elevation angle ≠ 90° may be independently positioned at an orientation angle relative to the tangent of the rotation vector (i.e., with respect to the rotation of each rotationally distinct tensioning segment) of about -25° to about 0° (aligned with the tangent) or about 0° (aligned with the tangent) to about 25°. A negative orientation angle value indicates that the needle points toward the axis of rotation, while a positive orientation angle value indicates that the needle points away from the axis of rotation. For example, any given tensioned microneedle may be characterized by an orientation angle (°) 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 a value within a range between any of the aforementioned values ​​on either side of 0, e.g., from about -15 to about -8, from about 5 to about 12, etc. In many embodiments, each of the first and second tensioned microneedles may be positioned such that the entire needle body is tangentially aligned with the vector of rotation (i.e., orientation angle 0°) relative to the rotation of each rotationally distinct tensioned segment. The orientation angle is measured from a tangent plane passing through the center of the microneedle base to the center of the microneedle tip, as described above with respect to microneedles on wearable medical devices.

[0111] In some embodiments, each of the first and second tensioning microneedles may be independently characterized by a length of about 0.5 mm to about 3.5 mm. For example, each of the first and second microneedles may be independently characterized by a length of about 0.5, 0.8, 1.0, 1.2, 1.5, 1.8, 2.0, 2.2, 2.5, 2.8, 3.0, or 3.5 mm, or a range between any of the foregoing values, such as about 0.5 to about 0.8 mm. The length of the needles may be selected based on application needs. For example, shorter needles may be more comfortable for older users or in areas where the skin may be thinner. In many embodiments, the length of the tensioning microneedles may be selected to be longer than the microneedles of the wearable medical device. Alternatively, if the applicator has a means for extending the wearable medical device beyond the periphery of the applicator (e.g., an extendable docking platform), the length of the tensioning microneedles may be selected to be equal to or shorter than the microneedles of the wearable medical device.

[0112] In some embodiments, each of the first and second tensioning microneedles may be independently characterized by a diameter of about 1 μm to about 25 μm. For example, each of the first and second tensioning microneedles may be independently characterized by a diameter, in μm, of about 1, 2, 5, 8, 10, 12, 15, 18, 20, 22, or 25, or a range between any of the foregoing values, such as, for example, a range between about 8 and about 12. In some embodiments, any tensioning microneedle described herein may have a uniform or non-uniform diameter within the above ranges.

[0113] In some embodiments, the plurality of tensioning microneedles may be arranged in a circular or semicircular array extending around the axis of rotation, for example, the plurality of tensioning microneedles may be arranged in 1 to 5 arrays.

[0114] In some embodiments, the plurality of tensioning microneedles may be constructed from metal, plastic, rubber, silicone, or a combination thereof.

[0115] In many embodiments, the tensioning microneedles may be driven into the skin surface before rotation, while in other embodiments, the tensioning microneedles may operate by friction (e.g., with blunt rubber microneedles) rather than by puncturing the skin surface.

[0116] (Release mechanism) 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 retention element. The mechanism can include a button, compressing a plunger, a switch, etc. Upon disengaging the retention element, potential energy stored within the loaded communicating member can drive the wearable medical device back to its original state or to an at least partially unstretched state.

[0117] Additional Features In some embodiments, the described applicators may further include a docking platform for holding the wearable medical device within the applicator. In some embodiments, the docking platform may be extendable beyond the periphery of the applicator. For example, when tensioning the skin surface, it may be undesirable to have multiple microneedles of the wearable medical device contact the skin surface during tensioning. Thus, the docking platform may be configured to retract the wearable medical device away from the skin surface before tensioning and / or extend the wearable medical device toward the skin surface after tensioning.

[0118] In some embodiments, the described applicators may further include an actuation guide configured to mate with applicator guides on the first and second rotationally distinct segments. Alternatively, the applicator may include a docking platform for holding a wearable medical device within the applicator and an actuation guide configured to mate with an applicator guide on the docking platform. In some embodiments, the actuation guide may be a track in a stationary wall within the applicator. The track in the stationary wall of the applicator may be angled to accommodate rotation of the first and / or second rotationally distinct segments (see, e.g., FIGS. 7A and 7B). The actuation guide may facilitate independent rotation of the first and second rotationally distinct segments and therefore may be any structure. For example, the actuation guide may include a track, a pin, a gear, a friction-inducing component, etc.

[0119] How to apply In many embodiments, a method is described for attaching a wearable medical device (e.g., a wearable medical device of the present disclosure having a tensioning communication member) to a skin surface. The method may include providing an applicator described herein having a wearable medical device therein, 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 may further include contacting the applicator with a skin surface such that the chamber contacts the skin surface, engaging a mechanism for applying reduced pressure to the skin surface to create a stretched 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 of the wearable medical device are driven into the stretched skin surface.

[0120] In many embodiments, a method for attaching a wearable medical device (e.g., a wearable medical device of the present disclosure having a rolling communication member) to a skin surface is described. The method may include providing an applicator described herein having a wearable medical device therein, contacting the applicator to a skin surface such that the chamber contacts the skin surface, and engaging a mechanism for applying reduced pressure to the skin surface to create a stretched skin surface. The method may further include rotating a first rotationally distinct segment and rotating the rotationally distinct segment such that a plurality of first microneedles and a plurality of second microneedles are driven into the stretched skin surface.

[0121] In some embodiments, any of the methods described herein may further include engaging a tensioning actuator such that the plurality of tensioning microneedles in contact with the skin surface rotate to create a stretched skin surface.

[0122] In some embodiments, any method described herein may further include selecting a degree of rotation for rotating the first rotationally distinct segment and for rotating the second rotationally distinct segment, whether for loading a wearable medical device (e.g., having a tensioning communication member) or for driving a wearable medical device (e.g., having a rolling communication member).

[0123] In some embodiments, any of the methods described herein for attaching a wearable medical device may further include attaching a monitoring device to the wearable medical device.

[0124] In some embodiments, any of the methods described herein for attaching a wearable medical device to a skin surface may further include applying an auxiliary fixation article to the wearable medical device or to a wearable medical device having a monitoring device thereon. The auxiliary fixation article may be a bandage, a protective cover (e.g., waterproof / sweatproof), etc. In some embodiments, the auxiliary fixation article may include a backing material and a skin-compatible adhesive.

[0125] In some embodiments, a method for removing a wearable medical device from a skin surface is described. The method may include 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.

[0126] In some embodiments, a method for removing a wearable medical device from a skin surface is described. The method may include contacting an applicator with the wearable medical device on the skin surface, engaging a loading actuator in 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.

[0127] Monitoring Methods In many embodiments, a method for monitoring a biological signal is described. The method may include detecting the biological signal with a monitoring device affixed to a wearable medical device of the present disclosure attached to a skin surface.

[0128] In some embodiments, the biosignal may be selected from an electrical signal, a chemical signal, an optical radiation signal, or a combination thereof.

[0129] The method may further include attaching the wearable medical device to a skin surface.

[0130] The method may further include securing the monitoring device to a wearable medical device attached to the skin surface.

[0131] kit In many embodiments, a kit is described. The kit may include an applicator of the present disclosure and a set of instructions for attaching the wearable medical device to a skin surface.

[0132] In some embodiments, the kit may further include one or more wearable medical devices of the present disclosure.

[0133] In some embodiments, the kit may further include one or more monitoring devices.

[0134] In some embodiments, the kit may further include one or more auxiliary fixation items.

Claims

1. 1. An applicator for applying a wearable medical device to a skin surface, comprising: a loading actuator configured to counter-rotationally load a first rotationally distinct segment and a second rotationally distinct segment within the wearable medical device; a retention system for retaining the wearable medical device in a counter-rotationally loaded configuration; A skin tensioning system, a chamber surrounding an area in which the wearable medical device is housed with the applicator and configured to contact an area of ​​a skin surface; a skin tensioning system comprising: a mechanism for applying reduced pressure to the area of ​​the skin surface; a mechanism for releasing the wearable medical device from the counter-rotationally loaded configuration; The wearable medical device comprises: A base, a first rotationally distinct segment; and a second rotationally distinct segment at least partially surrounded by the first rotationally distinct segment; and a plurality of first microneedles located on the first rotationally distinct segment; a second plurality of microneedles located on the second rotationally distinct segment; and at least one communication member communicating the first rotationally distinct segment with the second rotationally distinct segment.

2. 1. An applicator for attaching a wearable medical device to a skin surface, comprising: a drive actuator configured to rotate a first rotationally distinct segment and to rotate a second rotationally distinct segment in the wearable medical device in an opposite rotation; A skin tensioning system, a chamber surrounding an area in which the wearable medical device is housed with the applicator and configured to contact an area of ​​a skin surface; a skin tensioning system comprising: a mechanism for applying reduced pressure to the area of ​​the skin surface; The wearable medical device comprises: A base, a first rotationally distinct segment; and a second rotationally distinct segment at least partially surrounded by the first rotationally distinct segment; and a plurality of first microneedles located on the first rotationally distinct segment; a second plurality of microneedles located on the second rotationally distinct segment; and at least one communication member communicating the first rotationally distinct segment with the second rotationally distinct segment.

3. 3. The applicator of claim 1 or 2, wherein the chamber is housed with the applicator body.

4. 3. The applicator of claim 1 or 2, wherein the chamber extends from the applicator body.

5. The applicator of any one of claims 1 to 4, wherein the mechanism for applying reduced pressure comprises an electric vacuum pump, a mechanical vacuum pump, a suction valve, a syringe, or a combination thereof.

6. The skin tensioning system comprises: a plurality of tensioning microneedles; 6. The applicator of claim 1, further comprising: a tensioning actuator configured to rotate the plurality of tensioning microneedles around an area within the applicator where the wearable medical device is housed.

7. The skin tensioning system comprises: further comprising a first rotationally different tensioning segment and a second rotationally different tensioning segment at least partially surrounding the first rotationally different tensioning segment; the plurality of tensioning microneedles comprises a plurality of first tensioning microneedles and a plurality of second tensioning microneedles; 7. The applicator of claim 6, wherein the plurality of first tensioning microneedles are located on the first rotationally distinct tensioning segment and the plurality of second tensioning microneedles are located on the second rotationally distinct tensioning segment.

8. 8. The applicator of claim 7, wherein the first rotationally distinct tensioning segment and the second rotationally distinct tensioning segment are each cylindrical ring shaped and concentrically arranged.

9. 9. The applicator of claim 7 or 8, wherein the plurality of first tensioning microneedles and the plurality of second tensioning microneedles are independently characterized by an elevation angle of about 40 to about 80 degrees, and each of the plurality of first tensioning microneedles is oriented such that a first microneedle tip faces a rotational direction opposite to a rotational direction faced by a second microneedle tip of each of the plurality of second tensioning microneedles.

10. 1. A method of attaching a wearable medical device to a stretched skin surface, comprising: Providing an applicator according to any one of claims 1 to 9, having the wearable medical device therein; 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 applicator with a skin surface such that the chamber contacts the skin surface; engaging the mechanism for applying reduced pressure to the skin surface to create a stretched skin surface; Releasing the wearable medical device from the counter-rotationally loaded configuration into the stretched skin surface.

11. 1. A method of attaching a wearable medical device to a stretched skin surface, comprising: Providing an applicator according to any one of claims 1 to 9, having the wearable medical device therein; contacting the applicator with a skin surface such that the chamber contacts the skin surface; engaging the mechanism for applying reduced pressure to the skin surface to create a stretched skin surface; 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 of the wearable medical device are driven into the stretched skin surface.

12. 12. The method of claim 10 or 11, further comprising engaging a tensioning actuator such that a plurality of tensioning microneedles in contact with the skin surface rotate to create a stretched skin surface.

13. A kit comprising: An applicator according to any one of claims 1 to 9; and instructions for attaching the wearable medical device to a skin surface.

14. The kit of claim 13 , further comprising one or more wearable medical devices.

15. 15. The kit of claim 13 or 14, further comprising a monitoring device.

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