Patent Application
20230020448
The following description relates to a needling device for needling of a subject's skin by a user such as a physician or any user. In certain embodiments, the subject is in need of inducing hair growth or hair follicle neogenesis, or is in need of preventing hair loss. For example, a needling device may be applied to a subject's skin for hair growth applications, or may also be used for wrinkle reduction, scar revision, hair removal, tattoo removal, and pigmentation.
Needling devices are typically used for tattoo removal or wrinkle reduction mechanisms by lightly penetrating a subject's skin and without penetrating deeper areas of a subject's skin or scalp. Needling devices have also been used for hair growth applications. However, conventional needling devices do not allow a user to easily achieve optimal therapeutic depth and puncture precision in these various treatments and procedures. Conventional needling devices fail to provide optimal needle dimensions, needle orientations, skin reference dimensions, motors, motor linkages, among other features, that allow optimal therapeutic depth and puncture precision.
In an aspect, a needling device includes a plurality of needles forming a needle array, and a motor assembly for driving the needle array.
Each of the plurality of needles may include a needle tip at one end, and may taper at a taper angle and along a taper length to a maximum needle diameter at the other end, and the maximum needle diameter may range from approximately 0.20 mm to approximately 0.24 mm.
The taper length may range from approximately 1 mm to approximately 2 mm.
The taper angle may range from approximately 5 degrees to approximately 15 degrees.
The needle tip may have a tip radius ranging from approximately 0.015 mm to approximately 0.025 mm.
In use, a skin reference surface of the needling device may be in contact with a subject's skin, and the skin reference surface may have a surface area ranging from approximately 45 mm2 to approximately 105 mm2.
In use, a skin reference surface of the needling device may be in contact with a subject's skin, and an average distance between each needle of the plurality of needles of the needle array and the skin reference surface may range from approximately 0.10 mm to approximately 2.5 mm.
A distance between each needle of the plurality of needles of the needle array and the skin reference surface may be the same for all needles.
A first distance between one of the plurality of needles of the needle array and the skin reference surface may be different than a second distance between another of the plurality of needles of the needle array and the skin reference surface.
The motor assembly may include a motor linkage, and the motor linkage may include a rotational component with a total mass ranging from approximately 0.5 grams to approximately 35 grams and a rotational radius ranging from approximately 1.5 mm to approximately 3.5 mm, and the motor linkage may include a linear component with a total mass ranging from approximately 1.5 grams to approximately 3.5 grams.
An actual penetration depth of the plurality of needles into a subject's skin may not exceed a depth setting on the needling device.
A mean value of an actual penetration depth of the plurality of needles may be at least 0.2 mm in response to a depth setting of the needling device of 0.5 mm, at least 0.6 mm in response to a depth setting of the needling device of 1.5 mm, and at least 0.75 mm in response to a depth setting of the needling device of 2.0 mm.
In use, an actual penetration depth of the plurality of needles may be at least 50% of a target depth based on a depth setting of the device for at least 45% of all needle strikes of the plurality of needles.
In use, an actual penetration depth of the plurality of needles may be at least 50% of a target depth based on a depth setting of the device for at least 35% of all needle strikes of the plurality of needles.
In use, an actual penetration depth of the plurality of needles may be at least 50% of a target depth based on a depth setting of the device for at least 25% of all needle strikes of the plurality of needles.
In use, an actual penetration depth of the plurality of needles may be at least 50% of a target depth based on a depth setting of the device for at least 15% of all needle strikes of the plurality of needles.
The needling device may further include a sheath assembly comprising the needle array and a main unit comprising the motor assembly.
In another aspect, a needling device includes a plurality of needles forming a needle array, and a motor assembly for driving the needle array, wherein each of the plurality of needles includes a needle tip at one end, and tapers at a taper angle and along a taper length to a maximum needle diameter at the other end, and the maximum needle diameter ranges from approximately 0.20 mm to approximately 0.24 mm.
In another aspect, a needling device includes a plurality of needles forming a needle array, and a motor assembly for driving the needle array, wherein each of the plurality of needles includes a needle tip at one end, and tapers at a taper angle and along a taper length to a maximum needle diameter at the other end, and wherein the taper length ranges from approximately 1 mm to approximately 2 mm.
In another aspect, a needling device includes a plurality of needles forming a needle array, and a motor assembly for driving the needle array, wherein each of the plurality of needles includes a needle tip at one end, and tapers at a taper angle and along a taper length to a maximum needle diameter at the other end, and wherein the taper angle ranges from approximately 5 degrees to approximately 15 degrees.
In another aspect, a needling device includes a plurality of needles forming a needle array, and a motor assembly for driving the needle array, wherein each of the plurality of needles includes a needle tip at one end, and tapers at a taper angle and along a taper length to a maximum needle diameter at the other end, and wherein the needle tip has a tip radius ranging from approximately 0.015 mm to approximately 0.025 mm.
In another aspect, a needling device includes a plurality of needles forming a needle array, and a motor assembly for driving the needle array, wherein, in use, a skin reference surface of the needling device is in contact with a subject's skin, and the skin reference surface has a surface area ranging from approximately 45 mm2 to approximately 105 mm2.
In another aspect, a needling device includes a plurality of needles forming a needle array, and a motor assembly for driving the needle array, wherein, in use, a skin reference surface of the needling device is in contact with a subject's skin, and an average distance between each needle of the plurality of needles of the needle array and the skin reference surface area ranges from approximately 0.10 mm to approximately 2.5 mm.
In another aspect, a needling device includes a plurality of needles forming a needle array, and a motor assembly for driving the needle array, wherein the motor assembly includes a motor linkage, and wherein the motor linkage includes a rotational component with a total mass ranging from approximately 0.5 grams to approximately 35 grams and a rotational radius ranging from approximately 1.5 mm to approximately 3.5 mm, and the motor linkage includes a linear component with a total mass ranging from approximately 1.5 grams to approximately 3.5 grams.
The foregoing summary, as well as the following detailed description, will be better understood when read in conjunction with the appended drawings. For the purpose of illustration, there is shown in the drawings certain embodiments of the present disclosure. It should be understood, however, that the invention is not limited to the precise arrangements and instrumentalities shown. The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate an implementation of systems and apparatuses consistent with the present invention and, together with the description, serve to explain advantages and principles consistent with the invention.
Before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The Figures and written description are provided to teach any person skilled in the art to make and use the inventions for which patent protection is sought. The invention is capable of other embodiments and of being practiced and carried out in various ways. Those skilled in the art will appreciate that not all features of a commercial embodiment are shown for the sake of clarity and understanding.
In addition, it is to be understood that the phraseology and terminology employed herein are for the purpose of description and should not be regarded as limiting. For example, the use of a singular term, such as, “a” is not intended as limiting of the number of items. Also the use of relational terms, such as but not limited to, “top,” “bottom,” “left,” “right,” “upper,” “lower,” “down,” “up,” “side,” are used in the description for clarity in specific reference to the Figures and are not intended to limit the scope of the invention or the appended claims. The terms “approximately,” “substantially,” “about”, and “around,” set a value described as such to equal any value ranging from plus or minus 5%. For example, a value of about 10 mm is equal to any value from 9.5 mm to 10.5 mm. Further, it should be understood that any one of the features of the invention may be used separately or in combination with other features. Other systems, methods, features, and advantages of the invention will be or become apparent to one with skill in the art upon examination of the Figures and the detailed description. It is intended that all such additional systems, methods, features, and advantages be included within this description, be within the scope of the present invention, and be protected by the accompanying claims.
Needling devices described herein may be used for a number of different procedures including, for example, hair growth applications, wrinkle reduction, scar revision, hair removal, tattoo removal, and pigmentation. Advantages of the needling devices described in this application include providing a set of needles and needle configuration, and a motor configuration that allows optimal and precise needling and achieving therapeutic depth and puncture precision in treatment.
It was believed until quite recently that follicle formation occurs but once in a lifetime (in utero), so that a mammal, and particularly a human, is born with a fixed number of follicles, which does not normally increase thereafter. Despite suggestions of the regenerative capacity of the adult mammalian skin to recreate the embryonic follicle, until recently, follicle neogenesis was not proven because of the lack of tools needed to demonstrate the occurrence or hair follicle neogenesis (see, Argyris et al, 1959, Dev. Biol. 1: 269-80; Miller, 1973, J. Invest. Dermatol. 58: 1-9; and ligman, 1959, Ann NY Acad Sci 83: 507-511).
It has been proposed, however, that hair follicle neogenesis can be associated with wound healing in animals (e.g., rabbits, mice). See, Stenn & Paus, 2001, Physiol. Revs. 81:449-494. More recently, a series of murine experiments definitively showed that hair follicle-derived epithelial stem cell progenitors migrate out of the follicle and contribute to the re-epithelialization of injured skin (see, Morris et al, 2004, Nature Biotechnology 22:411-417; Ito et al, 2004, Differentiation 72:548-57; and Ito et al, 2005, Nature Medicine 11: 1351-1354). In animal studies designed to explore the role of Wnt in hair follicle development, Fathke showed that prolonged activation of Wnt signaling during wound healing in mice resulted in generation of rudiments of hair follicles but did not result in the formation of hair follicles or growth of more hair (Fathke et al, 2006, BMC Cell Biol. 7:4).
As noted by Fathke, cutaneous repair in adult mammals following full thickness wounding is understood to result in scar tissue and the loss of the regenerative capability of the hair follicle. Severe wounds and burns are usually associated with a form of cutaneous repair that results in scar tissue and no hair follicles (see, Fathke et al, 2006, BMC Cell Biol. 7:4). However, in a mouse study, Cotsarelis showed that physically disrupting the skin and existing follicles, in a defined fashion, can lead to follicle neogenesis (Ito et al, 2007, Nature 447:316-321). Cotsarelis showed that following closure of large healed wounds created by full thickness excision (FTE) (1 cm2 square wounds) in mice, new hairs are formed at the center of the wound (Ito et al, 2007, Nature 447:316-321). (Argyris, 1976, Amer J Pathol 83:329-338).
Other preclinical studies have identified a therapeutic window after epithelial disruption where the skin reverts to an embryonic state, allowing manipulation of skin and follicle phenotype by addition of compounds. For example, because new hair patterns after wounding are not predetermined, the regulatory pathways relevant to follicle formation (e.g. Wnt, EGFR) can be influenced dramatically, e.g., to increase the number and size of follicles. See, Ito et al. Nature. 2007; 447(7142):316-320; Fathke et al. BMC Cell Biol. 2006; 7:4; Snippert et al. Science. 2010; 327(5971): 1385-1389.
The needling devices, the needles, and the methods described herein provide optimal and precise needling to achieve optimized therapeutic outcome.
Needling devices in accordance with various examples of the present disclosure may be used for hair growth, wrinkle reduction, scar revision, hair removal, tattoo removal, among other treatments.
Needling devices and treatments using needling devices in accordance with various examples of the present disclosure may also be used in combination with one or more agents. In one aspect, the agent is an agent that promotes hair growth. In one aspect, the agent is an agent that is useful in reducing wrinkles. In one aspect, the agent is an agent that is useful in scar revision. In one aspect, the agent is an agent that is useful in hair removal. In one aspect, the agent is an agent that is useful in tattoo removal. In one aspect, the agent is an agent that is useful in pigmentation. In another aspect, the agent is a topical anesthetic.
Stem cells are thought to be activated in the hair bulge 20 under wound healing conditions, along with the induction of hair growth-related genes, such as VEGF, beta-catenin, and Wnt signaling molecules. The most important stem cells are located at the bulge 20 so that it is desirable to disrupt the skin 5 deep enough to disrupt the sebaceous gland 18, bulge 20, or hair papilla of existing follicle structures.
At the same time, it is important to minimize adverse effects. An optimization of clinical effects while minimizing adverse effects is desirable. It is also desirable to localize wound healing effects at the most therapeutically relevant depth and optimize the clinical effect while minimizing the potential for adverse effects that result therefrom.
The needling devices, needles, and methods described herein provide optimal puncture depth so as to maximize therapeutic effect while minimizing adverse effects
Referring to
Accordingly, even if different treatments are intended to achieve the same disruption depth, clinical effects and actual results will vary depending on the initial dynamic at first encounter between the skin surface and needle tip. Initial dynamics are affected by aspects of a microneedling device including, but not limited to, needle dimensions as described in Section 5.2.1, needle array orientation as described in Section 5.2.2, and the motor and motor linkage as described in Section 5.2.3. In addition to the significance of treatment depth as measured by needle extension tests, the actual penetration of the stratum corneum provides improved clinical effects depending on initial skin puncture dynamics.
Referring to
In the above described examples, a longer taper length L and a smaller taper angle α may enable a needle to less abruptly puncture the dermis over the course of needle penetration. A smaller diameter d may optimize the diameter for greater skin disruption with the ability to achieve full puncture. A slightly rounded initial tip may create more significant initial puncture to allow the needle to puncture more deeply. According to various examples, the needle diameter d may range from approximately 0.20 mm to approximately 0.24 mm. The diameter d includes at least 0.20 mm, at least 0.21 mm, at least 0.22 mm, at least 0.23 mm, at least 0.24 mm, at most 0.20 mm, at most 0.21 mm, at most 0.22 mm, at most 0.23 mm, and at most 0.24 mm. According to various examples, the taper length L may range from approximately 1 mm to approximately 2 mm. The taper length L includes at least 1 mm, at least 1.1 mm, at least 1.2 mm, at least 1.3 mm, at least 1.4 mm, at least 1.5 mm, at least 1.6 mm, at least 1.7 mm, at least 1.8 mm, at least 1.9 mm, at least 2 mm, at most 1 mm, at most 1.1 mm, at most 1.2 mm, at most 1.3 mm, and at most 1.4 mm, at most 1.5 mm, at most 1.6 mm, at most 1.7 mm, at most 1.8 mm, at most 1.9 mm, and at most 2 mm. According to various examples, the taper angle α may range from approximately 5 degrees to approximately 15 degrees. The taper angle α includes at least 5 degrees, at least 6 degrees, at least 7 degrees, at least 8 degrees, at least 9 degrees, at least 10 degrees, at least 11 degrees, at least 12 degrees, at least 13 degrees, at least 14 degrees, at least 15 degrees, at most 5 degrees, at most 6 degrees, at most 7 degrees, at most 8 degrees, at most 9 degrees, at most 10 degrees, at most 11 degrees, at most 12 degrees, at most 13 degrees, at most 14 degrees, at most 15 degrees. According to various examples, the needle tip radius r may range from approximately 0.015 mm to 0.025 mm. The needle tip radius r includes at least 0.015 mm, at least 0.016 mm, at least 0.017 mm, at least 0.018 mm, at least 0.019 mm, at least 0.02 mm, at least 0.021 mm, at least 0.022 mm, at least 0.023 mm, at least 0.024 mm, at least 0.025 mm, at most 0.015 mm, at most 0.016 mm, at most 0.017 mm, at most 0.018 mm, at most 0.019 mm, at most 0.02 mm, at most 0.021 mm, at most 0.022 mm, at most 0.023 mm, at most 0.024 mm, at most 0.025 mm.
A microneedling device is used by translating the device across a subject's skin in gliding strokes, maintaining contact with the skin. The part of the device in contact with the skin may be referred to as the skin reference surface, through which the vertically oscillating needles extend. For example, at some points in the oscillation cycle, the skin reference surface may be the only part of the device, other than the needles themselves, that is in contact with a subject's skin. One function of the skin reference surface is to control the exposed extension of the needles and to prevent excessive, unintended depth of penetration. Given the skin's tendency to retreat upon puncture, an optimized skin reference surface must also effectively hold the skin in place, preventing a greater amount of skin from stretching and allowing further “retreat”. This skin dynamic in response to initial puncture of the skin is also described above in Section 5.1.3 and in reference with
According to various examples, the surface area of the skin reference surface 58, 62 may range from approximately 45 mm2 to approximately 105 mm2. The surface area includes at least 45 mm2, at least 50 mm2, at least 55 mm2, at least 60 mm2, at least 65 mm2, at least 70 mm2, at least 75 mm2, at least 80 mm2, at least 85 mm2, at least 90 mm2, at least 95 mm2, at least 100 mm2, at least 105 mm2, at least 110 mm2, at least 115 mm2, at least 120 mm2, at least 125 mm2, at least 130 mm2, at least 135 mm2, at least 140 mm2, at least 145 mm2, at least 150 mm2, at least 155 mm2, at least 160 mm2, at least 165 mm2, at least 170 mm2, at least 175 mm2, at least 180 mm2, at least 185 mm2, at least 190 mm2, at least 195 mm2, at least 200 mm2, at least 205 mm2, at least 210 mm2, at least 215 mm2, at least 220 mm2, at least 225 mm2, at least 230 mm2, at least 235 mm2, at least 240 mm2, at least 245 mm2, at least 250 mm2, at least 255 mm2, at least 260 mm2, at least 265 mm2, at least 270 mm2, at least 275 mm2, at most 45 mm2, at most 50 mm2, at most 55 mm2, at most 60 mm2, at most 65 mm2, at most 70 mm2, at most 75 mm2, at most 80 mm2, at most 85 mm2, at most 90 mm2, at most 95 mm2, at most 100 mm2, at most 105 mm2, at most 110 mm2, at most 115 mm2, at most 120 mm2, at most 125 mm2, at most 130 mm2, at most 135 mm2, at most 140 mm2, at most 145 mm2, at most 150 mm2, at most 155 mm2, and at most 160 mm2 at most 165 mm2, at most 170 mm2, at most 175 mm2, at most 180 mm2, at most 185 mm2, at most 190 mm2, at most 195 mm2, at most 200 mm2, at most 205 mm2, at most 210 mm2, at most 215 mm2, at most 220 mm2, at most 225 mm2, at most 230 mm2, at most 235 mm2, at most 240 mm2, at most 245 mm2, at most 250 mm2, at most 255 mm2, at most 260 mm2, at most 265 mm2, at most 270 mm2, at most 275 mm2. As a result, the needling device 58, 62, 66 is optimized to have a greater skin reference surface area, thereby holding onto the skin and reducing its ability to retreat at the instant of puncture.
Another factor affecting the degree to which the skin can “retreat” is the effective distance between the reference surface and the needles. A needle that is close to the reference surface has a shorter length of skin. Governed by its modulus of elasticity, a shorter length of skin is less able to “tent” away from the penetrating needle than a longer distance, and therefore is more likely to receive greater needle puncture.
Referring back to
According to various examples, the average needle to reference surface distance may range from approximately 0.10 mm to 2.5 mm. The average needle to reference surface distance includes at least 0.1 mm, at least 0.2 mm, at least 0.3 mm, at least 0.4 mm, at least 0.5 mm, at least 0.6 mm, at least 0.7 mm, at least 0.8 mm, at least 0.9 mm, at least 1.0 mm, at least 1.1 mm, at least 1.2 mm, at least 1.3 mm, at least 1.4 mm, at least 1.5 mm, at least 1.6 mm, at least 1.7 mm, at least 1.8 mm, at least 1.9 mm, at least 2.0 mm, at least 2.1 mm, at least 2.2 mm, at least 2.3 mm, at least 2.4 mm, at least 2.5 mm, at most 0.1 mm, at most 0.2 mm, at most 0.3 mm, at most 0.4 mm, at most 0.5 mm, at most 0.6 mm, at most 0.7 mm, at most 0.8 mm, at most 0.9 mm, at most 1.0 mm, at most 1.1 mm, at most 1.2 mm, at most 1.3 mm, at most 1.4 mm, at most 1.5 mm, at most 1.6 mm, at most 1.7 mm, at most 1.8 mm, at most 1.9 mm, at most 2.0 mm, at most 2.1 mm, at most 2.2 mm, at most 2.3 mm, at most 2.4 mm, at most 2.5 mm. By using a linear array of needles with a close-fitting reference surface, the needling device 58, 62, 66 has a lower, optimized distance between its needles and the closest edge of the reference surface compared with other devices such as devices having a circular orientation of needles.
In an example, a needling device according to the present disclosure may have a motor and a motor linkage which provides a tighter attachment and linkage between all components of the motor assembly. A greater inertia of linkage, motor, and moving shaft increases the kinetic energy at time of impact and increases the ability to effect full puncture. In addition, a greater stiffness of linkage reduces the mechanical yield of the linkage upon impact and increases the ability to transfer kinetic energy to the skin and disrupt the surface, thus reducing skin's ability to retreat and allowing greater penetration.
Still referring to
According to various examples, the mass of the rotational component in a motor linkage of a needling device according to an example of the present disclosure may range from approximately 0.5 grams to approximately 35 grams. The mass of the rotational component includes at least 0.5 g, at least 1.0 g, at least 2.0 g, at least 3.0 g, at least 4.0 g, at least 5.0 g, at least 6.0 g, at least 7.0 g, at least 8.0 g, at least 9.0 g, at least 10.0 g, at least 11.0 g, at least 12.0 g, at least 13.0 g, at least 14.0 g, at least 15.0 g, at least 16.0 g, at least 17.0 g, at least 18.0 g, at least 19.0 g, at least 20.0 g, at least 21.0 g, at least 22.0 g, at least 23.0 g, at least 24.0 g, at least 25.0 g, at least 26.0 g, at least 27.0 g, at least 28.0 g, at least 29.0 g, at least 30.0 g, at least 31.0 g, at least 32.0 g, at least 33.0 g, at least 34.0 g, at least 35.0 g, at most 0.5 g, at most 1.0 g, at most 2.0 g, at most 3.0 g, at most 4.0 g, at most 5.0 g, at most 6.0 g, at most 7.0 g, at most 8.0 g, at most 9.0 g, at most 10.0 g, at most 11.0 g, at most 12.0 g, at most 13.0 g, at most 14.0 g, at most 15.0 g, at most 16.0 g, at most 17.0 g, at most 18.0 g, at most 19.0 g, at most 20.0 g, at most 21.0 g, at most 22.0 g, at most 23.0 g, at most 24.0 g, at most 25.0 g, at most 26.0 g, at most 27.0 g, at most 28.0 g, at most 29.0 g, at most 30.0 g, at most 31.0 g, at most 32.0 g, at most 33.0 g, at most 34.0 g, and at most 35.0 g. According to various examples, the radius of the rotational component in a motor linkage of a needling device according to an example of the present disclosure may range from approximately 1.5 mm to approximately 3.5 mm. The radius of the rotational component includes at least 1.5 mm, at least 2.0 mm, at least 2.5 mm, at least 3.0 mm, at least 3.5 mm, at most 1.5 mm, at most 2.0 mm, at most 2.5 mm, at most 3.0 mm, at most 3.5 mm. Based on the rotational mass and rotational radius used, a rotational inertia may be calculated using the inertia formula provided above. In one example where the rotational mass is approximately 1.34 g and the rotational radius is approximately 2.5 mm, the rotational inertia is approximately 4.19E-06 g*m2. According to various examples, the mass of the linear component in a motor linkage of a needling device according to an example of the present disclosure may range from approximately 1.5 grams to approximately 3.5 grams. The mass of the linear component includes at least 1.5 g, at least 2.0 g, at least 2.5 g, at least 3.0 g, at least 3.5 g, at most 1.5 g, at most 2.0 g, at most 2.5 g, at most 3.0 g, at most 3.5 g. In an example, the linear mass may be approximately 2.25 g.
With respect to materials used which impact the material stiffness and, in turn, the linkage stiffness, a motor linkage of a needling device according to an example of the present disclosure may be made of metals, polymers, glass, and combinations thereof. For example, the linkage is made of a combination of one or more of stainless steel, aluminum, PEEK, glass-filled polymer, and glass-filled metal.
A needle depth measurement tissue study has been conducted for the determination of needle depth precision during microneedling procedures using a needling device according to an example of the present disclosure. This study was completed with samples of porcine skin at targeted depths of 0.5 mm, 1.5 mm, and 2.0 mm. As an acceptance criteria, dye penetration associated with a needle track did not exceed targeted depth settings of the core.
Background. This study used excised porcine skin and contained only epidermis and dermis. All subcutaneous layers were removed by the skin supplier. The needling device according to an example of the present disclosure included a reusable cordless electromechanical core enclosed in a single-use disposable sterile sheath containing the needle array. The needles used in the needling device were solid core 32 gauge needles that do not cut tissue in the same manner as a hollow core needle. The solid core needles puncture the stratum corneum and epidermis during the microneedling procedure, separating elastin and collagen bundles of the dermis. This separation manifests as deformation and gaps among the collagen bundles of the dermis. In vivo, the viscoelastic properties of the tissue cause the dermis to recoil after needle retraction, making the needle penetration wound or “track” difficult to visualize in a simple H&E stain biopsy. As a result, observation and characterization of these needle punctures without additional visualization is difficult.
A Franz chamber-approach test fixture was developed to allow the sample to be pressurized post-needling to infuse dye into the needled tissue which remains stretched to prevent recoil of the tissue. The sample remained in radial tension throughout multiple experimental steps: microneedling, pressured infusion of pigment, rinsing, and application of fixative. A conservative, clinically relevant model was constructed to approximate conditions that could allow greatest needle penetration depth, including: the skin being stretched very taut, the subcutaneous fat being removed, and needling at a density relevant to clinical use.
Equipment and Materials. The study was conducted using a needling device according to an example of the present disclosure, including a needle dimension as described in Section 5.2.1, a needle array orientation as described in Section 5.2.2, and a motor and motor linkage as described in Section 5.2.3, and porcine skin. Post-procedure, all samples were prepared for histological analysis using H&E staining. The following equipment and materials were used:
Testing Methodology.
Each tissue section is analyzed for (1) physical dimensions including maximum sample thickness and maximum sample length, (2) needle puncture count with physical puncture wounds being defined as any observation that penetrated the stratum corneum and punctured the epidermis, the measurement being made from the outer stratum corneum surface and all needle tracks being counted, and (3) needle track dye depth with the maximum depth of dye penetration being visible below each obvious needle track and the measurement being made from the outer stratum corneum surface. All histological sections are digitized for analysis. All measurements are made using the DDS slide imaging software provided by Mass Histology Service.
Results. Three tissue samples were evaluated, each sample being sectioned as illustrated in
Background. This study compared needle depths of a needling device according to an example of the present disclosure with other needling devices. The study was conducted using a needling device according to an example of the present disclosure, including a needle dimension as described in Section 5.2.1, a needle array orientation as described in Section 5.2.2, and a motor and motor linkage as described in Section 5.2.3, a needling device manufactured by manufacturer A, and a needling device manufactured by manufacturer B.
Testing Methodology. The surface area of three tissue samples were needled, one sample for each of the needling device of the present disclosure, manufacturer A's needling device, and manufacturer B's needling device. All needling devices were calibrated to needling at the 1.0 mm setting including the needling device of the present disclosure, manufacturer A's needling device, and manufacturer B's needling device. Twelve passes were applied through the dye (six passes in an east to west direction, and six passes in a north to south direction), at clinically relevant translation speed (2 cm/s). Pressure was applied post-needling at 5-10 psi for twenty seconds. The sample was removed from the fixture, washed and immersed in formalin.
Results.
The following is a summary of the results of the study comparing manufacturer A's needling device, manufacturer B's needling device, and the needling device according to an example of the present disclosure. For brevity, manufacturer A's device is referred to as device A, manufacturer B's device is referred to as device B, and the needling device according to an example of the present disclosure is referred to as device X
The favorable depth verification results as describe above are attributed to the improved structural features described throughout the present disclosure. All tests yielding favorable results were performed using a needling device according to an example of the present disclosure, including a needle dimension as described in Section 5.2.1, a needle array orientation as described in Section 5.2.2, and a motor and motor linkage as described in Section 5.2.3.
It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. It is understood, therefore, that the invention disclosed herein is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims.
This application claims the benefit of priority to U.S. Provisional Patent Application No. 62/944,232, filed Dec. 5, 2019, which is hereby incorporated by reference in its entirety for all purposes.
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/US2020/063194 | 12/4/2020 | WO |
| Number | Date | Country | |
|---|---|---|---|
| 62944232 | Dec 2019 | US |
