# US 2016/0249983 A1 · Skin treatment device providing optical coupling to skin tissue > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2016/0249983 A1 - Document ID: US20160249983A1 - Status: Published application - Kind: A1 - Application number: 15/033,807 - Filed: 2014-11-06 - Published: 2016-09-01 - Earliest claimed: 2013-11-07 - Assignees: Koninklijke Philips N.V. - Applicants: Koninklijke Philips N.V. - Inventors: JONATHAN ALAMBRA PALERO; MARTIN JURNA; BABU VARGHESE; MARGARET RUTH HORTON - Web page: https://patentgrep.com/patent/US20160249983A1 ## CPC - A61B 18/203: {applying laser energy to the outside of the body} - A61B 2017/00026: {Conductivity or impedance, e.g. of tissue} - A61B 2017/00057: {Light} - A61B 2018/0047: {Upper parts of the skin, e.g. skin peeling or treatment of wrinkles} - A61B 2018/00773: {Sensed parameters} - A61B 2018/20355: {Special scanning path or conditions, e.g. spiral, raster or providing spot overlap} - A61B 2018/20361: {with redirecting based on sensed condition, e.g. tissue analysis or tissue movement} - A61B 2090/065: {for measuring contact or contact pressure} - A61B 2562/0247: Pressure sensors - A61B: DIAGNOSIS; SURGERY; IDENTIFICATION (usefulness limited to only animals A61D) ## Abstract The invention provides a non-invasive skin treatment device (200) comprising: a light source (10) constructed for emitting treatment light (15), an optical system (20) constructed for focusing the treatment light along an optical axis (OA) to a focus position (320) inside the skin tissue (300), and an indenter (30) comprising a skin contact surface (34) having an aperture (A1) at a distance from the optical system for allowing the treatment light to be focused through the aperture into the skin tissue. The indenter is configured and constructed for generating, in a cross-section of the aperture taken along the optical axis and along a cross-section direction wherein the aperture has a width dimension, a maximally curved protrusion of skin tissue freely protruding through the aperture towards the optical system by pressing the indenter against the skin surface of a specific skin type with a pressure exceeding a predefined pressure, a skin surface of said maximally curved protrusion having a radius of curvature (RC) at an intersection with the optical axis. The optical system is configured and constructed for generating a focused beam of the treatment light having, in said cross-section of the aperture at said intersection, a wave front with a radius of curvature ranging between 75% and 125% of said radius of curvature (RC) of the skin surface of said maximally curved protrusion. ## Claims ### Claim 1 A skin treatment device for light-based treatment of skin tissue, the skin treatment device comprising: a light source constructed for emitting treatment light, an optical system constructed for focusing the treatment light along an optical axis to a focus position inside the skin tissue, and an indenter comprising a skin contact surface having an aperture (A1, An) at a distance from the optical system for allowing the treatment light to be focused through the aperture (A1, An) into the skin tissue, the indenter and the aperture (A1, An) being configured and constructed for generating, in a cross-section of the aperture (A1, An) taken along the optical axis (OA, OAn) and along a cross-section direction wherein the aperture (A1, An) has a width dimension (d1, dn), a maximally curved protrusion of skin tissue freely protruding through the aperture (A1, An) towards the optical system when the indenter is pressed against the skin surface of a specific skin type with a pressure exceeding a predefined pressure above which for the specific skin type the freely protruding curved protrusion remains constant, a skin surface of said maximally curved protrusion having a radius of curvature (RC, RCn) at an intersection with the optical axis (OA, OAn), the optical system being configured and constructed for generating a focused beam of the treatment light having, in said cross-section of the aperture (A1, An) at said intersection, a wave front (WF) with a radius of curvature ranging between 75% and 125% of said radius of curvature (RC, RCn) of the skin surface of said maximally curved protrusion. ### Claim 2 (depends on 1) The skin treatment device according to claim 1, wherein said width dimension (d1, dn) of the aperture (A1, An) is less than 2 millimeter. ### Claim 3 (depends on 2) The skin treatment device according to claim 2, wherein the predefined pressure is 1.43 Newton per square centimeter. ### Claim 4 (depends on 1) The skin treatment device according to claim 1, wherein the radius of curvature of the wave front (WF) ranges between 95% and 105% of said radius of curvature (RC, RCn) of the skin surface of the maximally curved protrusion. ### Claim 5 (depends on 1) The skin treatment device according to claim 1, wherein the indenter is removably attached to the skin treatment device and is replaceable by a further indenter having a further aperture different from the aperture (A1, An). ### Claim 6 (depends on 1) The skin treatment device according to claim 1, wherein a dimension of the aperture (A1, An) in a direction transverse to the cross-section direction of the aperture (A1, An) is larger than 2 millimeter. ### Claim 7 (depends on 1) The skin treatment device according to claim 1, wherein the optical system is configured and constructed to generate a plurality of spatially separate focusing positions inside the skin tissue, and wherein the indenter comprises a plurality of apertures (An) each associated with a respective one of said plurality of focusing positions and each configured and constructed for generating a maximally curved protrusion of the skin tissue, the optical system being configured and constructed for generating a plurality of focused beams of the treatment light each having, in said cross-section of the associated aperture (A1, An) at said intersection, a wave front (WF) with a radius of curvature ranging between 75% and 125% of said radius of curvature (RCn) of the skin surface of said maximally curved protrusion. ### Claim 8 (depends on 1) The skin treatment device according to claim 1, wherein the indenter is attached to the skin treatment device via a resilient element. ### Claim 9 (depends on 1) The skin treatment device according to claim 1, wherein the skin treatment device comprises a pressure sensor for measuring the pressure with which the indenter, in use, is pressed against the skin surface, and a control circuit configured to control the light source to emit the treatment light only when the pressure measured by the pressure sensor exceeds the predefined pressure. ### Claim 10 (depends on 1) The skin treatment device according to claim 1, wherein the skin treatment device further comprises a curvature sensor for sensing a position and/or a curvature of the maximally curved protrusion at the intersection with the optical axis (OA, OAn). ### Claim 11 (depends on 10) The skin treatment device according to claim 10, wherein the curvature sensor is selected from a list comprising: optical sensor, capacitive sensor, reflected light sensor. ### Claim 12 (depends on 10) The skin treatment device according to claim 10, wherein the optical system is configured for adapting a location of the focus position inside the skin tissue in response to a signal from the curvature sensor. ### Claim 13 (depends on 10) The skin treatment device according to claim 10, wherein the curvature sensor is configured for focusing reflected treatment light, which is reflected from the skin surface of the maximally curved protrusion, onto a detector. ### Claim 14 (depends on 1) The skin treatment device according to claim 1, wherein the aperture (A1, An) has a circular, elliptical, square, rectangular or polygonal shape. ### Claim 15 (depends on 1) The skin treatment device according to claim 1, wherein the aperture (A1, An) comprises a circumferential edge having a radius of curvature (R1) in a range between 25 micrometer and 200 micrometer, preferably between 50 micrometer and 150 micrometer. ### Claim 16 (depends on 1) The skin treatment device according to claim 1, wherein the treatment light has a wavelength in a range between 350 nanometer and 10 micrometer, preferably in a range between 400 nanometer and 3 micrometer.