• Title/Summary/Keyword: Curvature of skin

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Principle and Mechanism of Double Eyelid Formation

  • Inchang Cho
    • Archives of Plastic Surgery
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    • v.50 no.2
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    • pp.142-147
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    • 2023
  • Some of Asian eyelids have double fold and some do not. Many people tend to prefer double eyelid in aesthetic and functional reasons. Since the mechanism of double eyelid is bonding the eyelid skin to the eye-opening tissue, the principle of double eyelid surgery is also connecting the eyelid skin to levator component. Double eyelids are differentiated by their shape according to the height and curvature. The double eyelid surgery procedure is divided into incision method and nonincision method. And the incision method is subdivided into double fold line design, skin and oculi muscle incision or excision, pretarsal or preaponeurotic soft tissue excision, fixation of posterior lamella to anterior lamella, and skin suture. The nonincision method is to connect the posterior lamella and the anterior lamella as a thread only without an incision. A successful double eyelid surgery creates a fold well-balanced in height, curvature, and depth of the fold based on patient's preference. In this article, the author's own methods of performing surgery are described, with a step-by-step guide and surgical tips.

Smart Wrist Band Considering Wrist Skin Curvature Variation for Real-Time Hand Gesture Recognition (실시간 손 제스처 인식을 위하여 손목 피부 표면의 높낮이 변화를 고려한 스마트 손목 밴드)

  • Yun Kang;Joono Cheong
    • The Journal of Korea Robotics Society
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    • v.18 no.1
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    • pp.18-28
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    • 2023
  • This study introduces a smart wrist band system with pressure measurements using wrist skin curvature variation due to finger motion. It is easy to wear and take off without pre-adaptation or surgery to use. By analyzing the depth variation of wrist skin curvature during each finger motion, we elaborated the most suitable location of each Force Sensitive Resistor (FSR) to be attached in the wristband with anatomical consideration. A 3D depth camera was used to investigate distinctive wrist locations, responsible for the anatomically de-coupled thumb, index, and middle finger, where the variations of wrist skin curvature appear independently. Then sensors within the wristband were attached correspondingly to measure the pressure change of those points and eventually the finger motion. The smart wrist band was validated for its practicality through two demonstrative applications, i.e., one for a real-time control of prosthetic robot hands and the other for natural human-computer interfacing. And hopefully other futuristic human-related applications would be benefited from the proposed smart wrist band system.

Structural behavior of aluminum reticulated shell structures considering semi-rigid and skin effect

  • Liu, Hongbo;Chen, Zhihua;Xu, Shuai;Bu, Yidu
    • Structural Engineering and Mechanics
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    • v.54 no.1
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    • pp.121-133
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    • 2015
  • The aluminum dome has been widely used in natatorium, oil storage tank, power plant, coal, as well as other industrial buildings and structures. However, few research has focused on the structural behavior and design method of this dome. At present, most designs of aluminum alloy domes have referred to theories and methods of steel spatial structures. However, aluminum domes and steel domes have many differences, such as elasticity moduli, roof structures, and joint rigidities, which make the design and analysis method of steel spatial structures not fully suitable for aluminum alloy dome structures. In this study, a stability analysis method, which can consider structural imperfection, member initial curvature, semi-rigid joint, and skin effect, was presented and used to study the stability behavior of aluminum dome structures. In addition, some meaningful conclusions were obtained, which could be used in future designs and analyses of aluminum domes.

Development of Ergonomic Leg Guard for Baseball Catchers through 3D Modeling and Printing

  • Lee, Hyojeong;Eom, Ran-i;Lee, Yejin
    • Journal of Fashion Business
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    • v.20 no.3
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    • pp.17-29
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    • 2016
  • To develop baseball catcher leg guards, 3-dimensional (3D) methodologies, which are 3D human body data, reverse engineering, modeling, and printing, optimized guard design for representative positions. Optimization was based on analysis of 3D body surface data and subjective evaluation using 3D printing products. Reverse engineering was used for analysis and modeling based on data in three postures: standing, $90^{\circ}$ knee flexion, and $120^{\circ}$ knee flexion. During knee flexion, vertical skin length increased, with the thigh and knee larger in anterior area compared to the horizontal dimension. Moreover, $120^{\circ}$ knee flexion posture had a high radius of curvature in knee movement. Therefore, guard designs were based on increasing rates of skin deformation and numerical values of radius of curvature. Guards were designed with 3-part zoning at the thigh, knee, and shin. Guards 1 and 2 had thigh and knee boundaries allowing vertical skin length deformation because the shape of thigh and knee significantly affects to its performance. Guard 2 was designed with a narrower thigh and wider knee area than guard 1. The guards were manufactured as full-scale products on a 3D printer. Both guards fit better in sitting than standing position, and guard 2 received better evaluations than guard 1. Additional modifications were made and an optimized version (guard 3) was tested. Guard 3 showed the best fit. A design approach based on 3D data effectively determines best fitting leg guards, and 3D printing technology can customize guard design through immediate feedback from a customer.

Application of a Composite Skin Equivalent using Collagen and Acellular Dermal Matrix as the Scaffold in a Mouse Model of Full-thickness Wound (콜라겐과 무세포진피를 이용한 혼합형 인공피부 개발 및 쥐 모델에서 창상치료 적용)

  • Lee, Dong Hyuck;Youn, Jin Chul;Lee, Jung Hee;Kim, In Seop
    • KSBB Journal
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    • v.29 no.1
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    • pp.42-49
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    • 2014
  • The aim of this study was to develop a composite human skin equivalent for wound healing. Collagen type1 and acellular dermal matrix powder were utilized as the scaffold with dermal fibroblasts and keratinocytes for the development of a composite human skin equivalent. Fibroblast maintained the volume of composite skin equivalent and also induced keratinocytes to attach and proliferate on the surface of composite skin equivalent. The composite human skin equivalent had a structure and curvature similar to those of real skin. Balb-C nu/nu mice were used for the evaluation of full-thickness wound healing effect of the composite human skin equivalent. Graft of composite skin equivalent on full-thickness wound promoted re-epithelialization and granulation tissue formation at 9 days. Given the average wound-healing time (14 days), the wound in the developed composite skin equivalent healed quickly. The overall results indicated that this three-dimensional composite human skin equivalent can be used to effectively enhance wound healing.

An Experimental Study of Turbulent Uniform Shear Flow in a Nearly Two-Dimensional $90^{\circ}$ Curved Duct (I) - Mean Flow Field- (2차원 $90^{\circ}$ 곡관에서 균일전단류의 특성에 대한 실험적 연구 (1) -평균유동장-)

  • 임효재;성형진;정명균
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.19 no.3
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    • pp.834-845
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    • 1995
  • An experimental study is made in a nearly two-dimensional 90.deg. curved duct to investigate the effects of interaction between streamline curvature and mean strain on turbulence. The initial shear at the entrance to the curved duct is varied by an upstream shear generator to produce five different shear conditions ; a uniform flow (UF), a positive weak shear (PW), a positive strong shear(PS), a negative weak shear (NW) and a negative strong shear(NS). With the mean field data of the case UF, variations of the momentum thickness, the shape factor and the skin friction over the convex(inner) surface and the concave (outer) surface are scrutinized quantitatively in-depth. It is found that, while the pressure loss due to curvature is insensitive to the inlet shear rates, the distributions of wall static pressure along both convex and concave surfaces are much influenced by the inlet shear rates.

Skin Damage Sustained During Head-and-Neck and Shoulder Radiotherapy Due to the Curvature of Skin and the Use of Immobilization Mask (머리-목 그리고 어깨의 방사선 치료 시 피부곡면과 고정장치로 인한 피부손상연구)

  • Kim, Soo-Kil;Jeung, Tae-Sig;Lim, Sang-Wook;Park, Yeong-Mouk;Park, Dahl
    • Progress in Medical Physics
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    • v.21 no.1
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    • pp.86-92
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    • 2010
  • The purpose of this study was to measure curvature contour skin dose using radiochromic film and TLD for a conventional open field. We also attempted to quantify the degradation of skin sparing associated with use of immobilization devices for high energy photon beams and to calculate the skin dose with a help of Monte Carlo (MC) simulation. To simulate head-and-neck and shoulder treatment, a cylindrical solid water phantom 11 cm in diameter was irradiated with 6 MV x-rays using $40{\times}40\;cm^2$ field at 100 cm source axis distance (SAD) to the center of the phantom. Aquaplastic mesh mask was placed on the surface of the cylindrical phantom that mimicked relevant clinical situations. The skin dose profile was obtained by taking measurements from $0^{\circ}$ to $360^{\circ}$ around the circumference of the cylindrical phantom. The skin doses obtained from radiochromic film were found to be 47% of the maximum dose of $D_{max}$ at the $0^{\circ}$ beam entry position and 61% at the $90^{\circ}$ oblique beam position without the mask. Using the mask (1.5 mm), the skin dose received was 59% at $0^{\circ}$ incidence and 78% at $80^{\circ}$ incidence. Skin dose results were also gathered using thin thermoluminescent dosimeters (TLD). With the mask, the skin dose was 66% at $0^{\circ}$ incidence and 80% at $80^{\circ}$ incidence. This method with the mask revealed the similar pattern as film measurement. For the treatments of the head-and-neck and shoulder regions in which immobilization mask was used, skin doses at around tangential angle were nearly the same as the prescription dose. When a sloping skin contour is encountered, skin doses may be abated using thinner and more perforated immoblization devices which should still maintain immoblization.

Pattern Development using the Curvature Plot of 3D Human Scan Data (3차원 인체의 곡률분포를 이용한 패턴 전개)

  • Jeong, Yeon-Hee;Hong, Kyung-Hi
    • Journal of the Korean Society of Clothing and Textiles
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    • v.32 no.9
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    • pp.1478-1486
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    • 2008
  • The human body composed of concave and convex curvatures, and the current 3D scanning technology which involves inherent measurement errors make it difficult to extract distinct curvature plot directly. In this study, a method of extracting the clear curvature plot and its application to the cycling pants design were proposed. We have developed the ergonomic pattern from the 3D human body reflecting cycling posture. For the ergonomic design line on the 3D human body, the 3D information on the lower part of four male bodies with flexed posture was analyzed. The 3D scan data of four subjects were obtained using Cyberware. As results, the iteration of the tessellated shell was executed 100 times to obtain optimized curvature plots of the muscles on the body surface, and the boundaries of the curvature plots were applied to the design lines. Maximum(Max-pattern) and mean curvature plots(Mean-pattern) were adopted in the design line of the cycling pants, and performance of those lines was compared with that of conventional princess line(Con-pattern). The average error of total area and length in the 2D pattern developed from the 3D flexed body surface in this study were very minimal($4.58cm^2$(0.19%) and 0.15mm(0.46%)), which was within the range of tolerable limits in clothing production. The pattern obtained from the flexed body reflecting cycling posture already included the contraction and extension of the cycling skin, so that the extra ease for movement and good fit was not need to be considered.

The cover of an ear thermometer probe as a split-thickness skin graft mold in external auditory canal reconstruction

  • Chae Rim Lee;Sungyeon Yoon;Ji Hun Kim;Jangyoun Choi;Kyoung Ho Park;Deuk Young Oh
    • Archives of Craniofacial Surgery
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    • v.24 no.4
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    • pp.198-201
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    • 2023
  • Maintaining the patency of the external auditory canal (EAC) during reconstruction is important because of its physiological role in hearing and immunological protective functions. The curved shape of the EAC presents a challenge when performing a skin graft. One of the key points for a successful skin graft is to ensure compression on the wound bed, and many novel methods, including prefabricated ear molds, have been reported for this purpose. In this study, we present a case of a skin graft performed to reconstruct a skin defect following excision of actinic keratosis in the EAC, using the cover of an ear thermometer probe as a mold for the graft to match the curvature of the EAC. This is an economical and practical method for secure compression dressing of a skin graft in the EAC.

A Feasibility Study of Constitution Discrimination Using a Measurement Device for Dynamic Friction Coefficients of the Back of a Hand (손등피부 운동 마찰계수 측정기를 이용한 체질 판별 가능성 연구)

  • Kim, Keun-Ho;Woo, Yung-Jae;Lee, Hae-Jung;Lee, Yu-Jung;Kim, Jong-Yeol
    • Journal of Sasang Constitutional Medicine
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    • v.22 no.4
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    • pp.20-29
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    • 2010
  • 1. Objectives Our goal is to observe the feasibility of constitution discrimination from computing quantitative roughness index from dynamic friction coefficients and their gradients with the measurement device of skin friction with 3-Axis load cell sensor. 2. Methods In the traditional Korean medicine, skin diagnosis is one of the examination methods to discriminate Sasang constitution since it was known that Tae-eumin has rough skin, and Soyangin has smooth one. It is based on the skin roughness on the back of one's hand for the discrimination. The measurement device of skin friction with 3-axis load cell sensor has been developed in order to provide quantitative skin roughness through dynamic friction coefficients. The effective interval of the coefficients is obtained from the automatic sampling algorithm to use their curvature and slope. Then, Fisher's discriminant function of them makes the discrimination. 3. Results The success rate of extracting the effective interval was about 90% and the discriminant accuracy between Tae-eumin and Soyangin was 70% and 68% for men and women, respectively. The entire methods showed the possibility to distinguish between Tae-eumin and Soyangin by using stochastic properties of roughness index, which can make the entire system to include the measurement, the computation of the roughness index and the discrimination of constitution automatical. 4. Conclusions The measurement device, the automatic sampling algorithm of dynamic friction coefficients and the constitution discrimination algorithm were developed, respectively, and their combination can become the serial and automatic procedure for quantitative and objective skin diagnosis, which mimics the movement of the Oriental medical doctors' skin diagnosis. It can be applied to healthcare as well as the diagnosis of constitution in a u-Health system soon.