title: Improvement in Laser-Irradiation Efficiency of Robot-Assisted Laser Hair Removal Through Pose Measurement of Skin Surface.
abstract: OBJECTIVE
  This study aims to improve the performance of an automatic laser hair removal (LHR) system by applying an algorithm that considers the curve and slant of the skin surface.
  
  
  BACKGROUND
  In an earlier research, a robot-assisted LHR system has been developed and validated for an almost flat skin or a relatively smooth curved part of the skin. For practical clinical applications, the feature of the robot-assisted LHR system is extended for real curved skins.
  
  
  METHODS
  A novel pose-measurement algorithm is developed and applied to the LHR system. This system detects a six-degree of freedom (DOF) pose of the skin surface using the pose-measurement algorithm. The main principle of this algorithm is finding the equation of a plane using three noncollinear points, which are obtained by sequential movement of a one dimensional laser sensor.
  
  
  RESULTS
  Evaluation of the proposed system was conducted. During the test, we demonstrated that the LHR device automatically and completely contacted the targets along the curved surface. The contact-accuracy test produced satisfactory outcome. The averages of the root mean square (RMS) of the position error and the RMS of the rotation were 1.4437 mm and 1.0982 degrees, respectively. The curvature measurement test produced a satisfactory average result of 0.0006 mm RMS error.
  
  
  CONCLUSIONS
  Using the proposed six-DOF pose-measurement algorithm, the performance of the robot-assisted LHR system could be significantly improved from the clinical point of view because most real skins have curved shapes.
authors.affiliation: 1 Interdisciplinary Program for Bioengineering, Seoul National University College of Engineering , Seoul, Korea.
authors.forename: Sungwoo
authors.initials: S
authors.lastname: Park
authors.affiliation: 1 Interdisciplinary Program for Bioengineering, Seoul National University College of Engineering , Seoul, Korea.
authors.forename: Hyoung-woo
authors.initials: HW
authors.lastname: Lim
authors.affiliation: 1 Interdisciplinary Program for Bioengineering, Seoul National University College of Engineering , Seoul, Korea.
authors.forename: Minwoo
authors.initials: M
authors.lastname: Cho
authors.affiliation: 2 Department of Dermatology, Seoul National University College of Medicine , Institute of Human-Environment Interface Biology, Seoul, Korea.
authors.forename: Dong-Hun
authors.initials: DH
authors.lastname: Lee
authors.affiliation: 3 JMO Dermatology , Seoul, Korea.
authors.forename: Wooseok
authors.initials: W
authors.lastname: Koh
authors.affiliation: 4 Department of Mechanical & Aerospace Engineering, Institute of Advanced Aerospace Technology, Seoul National University College of Engineering , Seoul, Korea.
authors.forename: Youdan
authors.initials: Y
authors.lastname: Kim
authors.affiliation: 2 Department of Dermatology, Seoul National University College of Medicine , Institute of Human-Environment Interface Biology, Seoul, Korea.
authors.forename: Jin Ho
authors.initials: JH
authors.lastname: Chung
authors.affiliation: 5 Department of Biomedical Engineering, Seoul National University College of Medicine , Seoul, Korea.|6 Institute of Medical and Biological Engineering, Seoul National University , Seoul, Korea.
authors.forename: Sungwan
authors.initials: S
authors.lastname: Kim
mesh_terms: D000465:Algorithms; D006204:Hair Removal / Q000295:instrumentation*; D006801:Humans; D053685:Laser Therapy; D054023:Lasers, Semiconductor; D008954:Models, Biological; D012371:Robotics; D013499:Surface Properties