JMO Dermatology

Seoul, South Korea

JMO Dermatology

Seoul, South Korea
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Lim H.-W.,Seoul National University | Cho M.,Seoul National University | Lee D.-H.,Seoul National University | Koh W.,JMO Dermatology | And 3 more authors.
Photomedicine and Laser Surgery | Year: 2017

Objective: We aimed to develop and validate a novel computer-assisted automated hair counting system for the quantitative evaluation of laser hair removal (LHR). Methods: We developed a computer-aided image processing system to count hairs on shaved skin and validated its performance through clinical trials. Five volunteers of Fitzpatrick skin type III-IV volunteered and were tested on both thighs. The system automatically detects hair and places a "+" sign on each hair site for every positive detection. This method allows clinicians to check whether a hair has been counted or not. We analyzed the difference in the hair counts between the proposed system (automatic) and those by human observers (manual). Results: The hair counts from the proposed system and the manual counts were compared. The percentage error between automatic and manual counting was <5% in each subject. The data of the two groups were statistically verified with Student's independent t-test. The averages were statistically equivalent between the two groups. The proposed system showed significant time saving in terms of counting. Conclusions: A dependable, accurate, and fast method of counting hairs on shaved skin through a computer-aided image processing system was developed and validated. The "+" signs on the image to indicate detection allows clinicians to compare with the original image and detect any omission or redundancy. The proposed system is expected to be reliable in analyzing the results of multiple skin-related treatments, including LHR and hair transplantation. Further, it is expected to be widely applicable for use in the clinic. © 2017, Mary Ann Liebert, Inc.


Koh W.,JMO Dermatology | Lim H.-W.,Seoul National University | Cho M.,Seoul National University | Lee D.-H.,Seoul National University | And 3 more authors.
Photomedicine and Laser Surgery | Year: 2017

Background and objective: Many laser devices have been developed over the past decades for various skin conditions. However, variations in the technical skill of physicians for laser skin treatment delivery have not yet been evaluated. This study evaluates the differences in omission and overlap percentages during simulated laser hair removal treatments among physicians at two clinics. Materials and methods: A laser beam detection kit was developed to record and collect laser irradiation from a diode laser device. Eight physicians (primary private clinic 4, tertiary referral hospital 4) were recruited to perform 80 trials of laser delivery simulation. The simulation process was captured in video frames by a camera built inside of the detection kit. The laser distribution map was reconstructed, and each physician's performance result was determined by a computer calculation. Results: Various assumption tests showed that each physician had different laser delivery skills. Four physicians from clinic A had an average omission rate of 13.4%, and four physicians from clinic B had an average omission rate of 19.7%. Regarding the average overlap rate of the two clinics, clinic A had a higher rate than clinic B (26.1% vs. 14.6%). Conclusions: The study's findings confirmed the differences of the technical skills among the physicians and between the two clinics. The proposed computer-assisted evaluation of technical skill is useful for assessing physicians' performance during laser skin treatments. © 2017, Mary Ann Liebert, Inc.


Lim H.-W.,Seoul National University | Park S.,Seoul National University | Noh S.,Seoul National University | Lee D.-H.,Seoul National University | And 6 more authors.
Photomedicine and Laser Surgery | Year: 2014

Background and Objective: The robot-assisted automatic laser hair removal (LHR) system is developed to automatically detect any arbitrary shape of the desired LHR treatment area and to provide uniform laser irradiation to the designated skin area. Methods: For uniform delivery of laser energy, a unit of a commercial LHR device, a laser distance sensor, and a high-resolution webcam are attached at the six axis industrial robot's end-effector, which can be easily controlled using a graphical user interface (GUI). During the treatment, the system provides real-time treatment progress as well as the total number of "pick and place" automatically. Results: During the test, it was demonstrated that the arbitrary shapes were detected, and that the laser was delivered uniformly. The localization error test and the area-per-spot test produced satisfactory outcome averages of 1.04mm error and 38.22mm2/spot, respectively. Conclusions: Results showed that the system successfully demonstrated accuracy and effectiveness. The proposed system is expected to become a promising device in LHR treatment. © Mary Ann Liebert, Inc. 2014.


Cho M.,Seoul National University | Lee D.-H.,Seoul National University | Kim Y.,Seoul National University | Koh W.,JMO Dermatology | And 3 more authors.
International Journal of Cosmetic Science | Year: 2016

Objective: Various cosmetics, medicines, and light and laser treatments have been increasingly developed to improve pigmentary skin alterations such as melasma, actinic lentigo and dyschromia. To determine the efficacy of these modalities in view of the changes in pigmentation, an objective and reliable device that has a comparable performance to that of physicians is required. We developed a novel photography-based skin pigmentation evaluation system and validated its accuracy and reliability with a newly proposed method. Methods: A novel photography-based system was developed that integrates a consistent photography setting and image processing diagnostic algorithms. To automatically detect areas of pigmentation, the diagnostic algorithms were applied to photographs, which were obtained from 31 female patients. To validate its performance in comparison with the physicians’ evaluation, five dermatologists independently evaluated the area of pigmentation. The clinical consensus area of pigmentation (CCAP) was calculated based on the consensus of five dermatologists’ to exclude subjectivity or bias, and it was compared with the pigmentation area determined by the system. Results: Forty-four photographs with pigmented areas were evaluated by the system and the physicians. In contrast to the individual physician assessments, CCAP reduced the error that occurred due to subjectivity and bias, particularly for areas with indistinct pigmentation, and it was set as the gold standard. The results from the system showed a mean accuracy of 92.1% and a standard deviation of 4.6% in comparison with CCAP. Conclusion: This pigmentation evaluation system can reproduce the physicians’ consensus, suggesting that this system can support the dermatologists’ objective evaluation of pigmentation. © 2015 Society of Cosmetic Scientists and the Société Française de Cosmétologie


Noh S.,Seoul National University | Koh W.S.,JMO Dermatology | Lim H.-W.,Seoul National University | Yoon C.,Seoul National University | And 4 more authors.
BioMedical Engineering Online | Year: 2014

Background: The uniform delivery of laser energy is particularly important for safe and effective laser hair removal (LHR) treatment. Although it is necessary to quantitatively assess the spatial distribution of the delivered laser, laser spots are difficult to trace owing to a lack of visual cues. This study proposes a novel preclinic tool to evaluate operator proficiency in LHR treatment and applies this tool to train novice operators and compare two different treatment techniques (sliding versus spot-by-spot).Methods: A simulation bed is constructed to visualize the irradiated laser spots. Six novice operators are recruited to perform four sessions of simulation while changing the treatment techniques and the presence of feedback (sliding without feedback, sliding with feedback, spot-by-spot without feedback, and spot-by-spot with feedback). Laser distribution maps (LDMs) are reconstructed through a series of images processed from the recorded video for each simulation session. Then, an experienced dermatologist classifies the collected LDMs into three different performance groups, which are quantitatively analyzed in terms of four performance indices.Results: The performance groups are characterized by using a combination of four proposed indices. The best-performing group exhibited the lowest amount of randomness in laser delivery and accurate estimation of mean spot distances. The training was only effective in the sliding treatment technique. After the training, omission errors decreased by 6.32% and better estimation of the mean spot distance of the actual size of the laser-emitting window was achieved. Gels required operators to be trained when the spot-by-spot technique was used, and imposed difficulties in maintaining regular laser delivery when the sliding technique was used.Conclusions: Because the proposed system is simple and highly affordable, it is expected to benefit many operators in clinics to train and maintain skilled performance in LHR treatment, which will eventually lead to accomplishing a uniform laser delivery for safe and effective LHR treatment. © 2014 Noh et al.; licensee BioMed Central Ltd.


Park S.,Seoul National University | Lim H.-W.,Seoul National University | Cho M.,Seoul National University | Lee D.-H.,Seoul National University | And 4 more authors.
Photomedicine and Laser Surgery | Year: 2016

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 data: 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. © Copyright 2016, Mary Ann Liebert, Inc. 2016.


PubMed | JMO Dermatology and Seoul National University
Type: Journal Article | Journal: Annals of dermatology | Year: 2015

The efficacy of the long-pulsed diode laser (LPDL) in hair removal is determined with various physical parameters. Recently, LPDLs with a larger spot size are commercially available; however, the independent effect of spot size on hair removal has not been studied.This study aimed to compare the efficacy of the LPDL in hair removal depending on the spot size.A randomized, evaluators-blind, intrapatient comparison (left vs. right) trial was designed. Ten healthy Korean women received three hair removal treatment sessions on both armpits with the 805-nm LPDL and followed for 3 months. A 1010 mm handpiece (D1) or a 1030 mm handpiece (D3) was randomly assigned to the right or left axilla. The fluence, pulse duration, and epidermal cooling temperature were identical for both armpits. Hair clearance was quantified with high-resolution photos taken at each visit. Postprocedural pain was quantified on a visual analogue scale. Adverse events were evaluated by physical examination and the patients self-report.The mean hair clearance at 3 months after three treatment sessions was 38.7% and 50.1% on the armpits treated with D1 and D3, respectively (p=0.028). Procedural pain was significantly greater in the side treated with D3 (p=0.009). Serious adverse events were not observed.Given that the pulse duration, fluence, and epidermal cooling were identical, the 805-nm LPDL at the three times larger spot size showed an efficacy improvement of 29.5% in axillary hair removal without serious adverse events.


PubMed | JMO Dermatology and Seoul National University
Type: Journal Article | Journal: International journal of cosmetic science | Year: 2016

Various cosmetics, medicines, and light and laser treatments have been increasingly developed to improve pigmentary skin alterations such as melasma, actinic lentigo and dyschromia. To determine the efficacy of these modalities in view of the changes in pigmentation, an objective and reliable device that has a comparable performance to that of physicians is required. We developed a novel photography-based skin pigmentation evaluation system and validated its accuracy and reliability with a newly proposed method.A novel photography-based system was developed that integrates a consistent photography setting and image processing diagnostic algorithms. To automatically detect areas of pigmentation, the diagnostic algorithms were applied to photographs, which were obtained from 31 female patients. To validate its performance in comparison with the physicians evaluation, five dermatologists independently evaluated the area of pigmentation. The clinical consensus area of pigmentation (CCAP) was calculated based on the consensus of five dermatologists to exclude subjectivity or bias, and it was compared with the pigmentation area determined by the system.Forty-four photographs with pigmented areas were evaluated by the system and the physicians. In contrast to the individual physician assessments, CCAP reduced the error that occurred due to subjectivity and bias, particularly for areas with indistinct pigmentation, and it was set as the gold standard. The results from the system showed a mean accuracy of 92.1% and a standard deviation of 4.6% in comparison with CCAP.This pigmentation evaluation system can reproduce the physicians consensus, suggesting that this system can support the dermatologists objective evaluation of pigmentation.

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