Analysis of Korean Facial Measurements for Sizing System of Face Wearable Products

Baekhee Lee,Nahyeon Lee,Younggeun Choi,Eunjin Jeon,Kwangae Park,Boyoung Park,Wonsup Lee,Hee-Eun Kim,Jeongrae Lee,Junghee Won,Hyoseon Kim,Younghyun Kim,Heecheon You 대한인간공학회 2015 대한인간공학회 학술대회논문집 Vol.2015 No.10

Objective: The present study is to analyze Korean facial dimensions and select facial key dimension candidates for establishing a sizing system of face wearable products such as dust mask and oxygen mask. Background: An anthropometric sizing system accommodating different facial characteristics of the target population can contribute to improving usability of the face wearable product. Method: Facial key dimension candidates were selected by correlation analysis among 19 facial dimensions. Korean facial sizes measured by KATS (2004, 2010) and Lee et al. (2013) were compared to Chinese facial sizes measured by Du et al. (2008) to each facial key dimension candidate. Results: Face length, bitragion breadth, bitragion-subnasale arc, and bitragion-pronasale arc were selected as facial key dimension candidates. The face length of Korean was 6.6 mm longer compared to that for Chinese; the bitragion-subnasale arc 17.4 mm shorter. Conclusion: The present study proposed four facial key dimensions for Korean face wearable product sizing systems. Found that Korean have longer face length and lower cheekbones compared to Chinese. Application: The facial key dimension and corresponding analysis result can be applied to design for sizing system of Korean facial wearable products.

The Effects of Age, Gender, and Hand on Force Control Capabilities of Healthy Adults

Lee, Baekhee,Lee, Mina,Yoh, Myeung Sook,You, Heecheon,Park, Hyunji,Jung, Kihyo,Lee, Byung Hwa,Na, Duk L.,Kim, Geon Ha SAGE Publications 2015 Human factors Vol.57 No.8

Comparison of Swallowing Characteristics in Normal Controls and Patients with Dysphagia

Baekhee Lee,Hyewon Lee,Myeongeun Yun,Mee Kyung Suh,Duk L. Na,Heecheon You 대한인간공학회 2013 대한인간공학회 학술대회논문집 Vol.2013 No.5

Objective: The present study is intended to compare swallowing characteristics between normal controls and patients with dysphagia through quantification of the pharyngeal movement. Background: The existing diagnoses of swallowing have been qualitatively conducted by a clinician referring to results of the VideoFluorocopic Swallowing Study (VFSS) or the Fiberoptic Endoscopic Evaluation of Swallowing (FEES); therefore, a quantitative methodology for assessment of the swallowing is required to diagnose dysphagia more accurately. Method: A three-step approach was applied in the study: (1) development of a swallowing measurement device consisting of an ultrasonic Doppler sensor to measure the pharyngeal movement, (2) establishment of five swallowing quantification measures (peak amplitude, duration, number of peaks, peak interval, and impulse of swallowing) by a swallowing signal preprocessing, (3) evaluation of the swallowing in 120 normal controls and 36 dysphagic patients by three-step protocol (S1. informed consent, S2. exercise, S3. swallowing session; type and volume: dry saliva, thin liquid 1, 3, 9 ml, and thick liquid 1, 3, 9 ml). Results: Swallowing signals of normal controls and dysphagic patients classified into 2 types (short-single: 39%; short-double: 43%) and 3 types (short-double: 58%; long-double: 33%; long-multiple: 9%), respectively. Dysphagic patients had difficulties in swallowing of 9 ml regardless of swallowing type. Highest peak amplitude, duration, number of peaks, average peak interval, and impulse of dysphagic patients were 1.3 times higher (t = 4.31, p < .001), 3 times longer (t = -11.15, p < .001), 2 times more (t = -6.73, p < .001), 2 times longer (t = -9.23, p < .001), and 1.3 times lower (t = 8.94, p < .001) than those of normal controls, respectively. Application: The swallowing characteristics of dysphagic patients can be applied to develop a diagnostic model which can evaluate quantitatively the existence and severity for dysphagia.

Development of a Design Factor Quantification Method to Increase a Grip Comfort of Outside Door Handle (ODH)

Baekhee Lee,Seunghoon Lee,Hayoung Jung,Jawon Lee,Teukgyu Choi,Mina Lee,Hogeun Kim,Eunha Kim,Hojun Jeon,Youngbum Cho,Seungwoo Seo,Heecheon You 대한인간공학회 2014 대한인간공학회 학술대회논문집 Vol.2014 No.11

Objective: The present study is to evaluate satisfaction of vehicle outside door handles (ODHs) by design factor for improving grip comfort. Background: Existing studies have mainly focused on size and/or shape of typical handles (e.g., cylindrical handle); therefore, a specialized research for ergonomic ODH design is needed. Method: Satisfaction (operation, shape, height, width, tilting angle, central radius (R), inside upper R, inside middle R, inside lower R, pressure distribution, and overall satisfaction) by design factor (2-level: section width; 3-level: central R, inside upper R, inside middle R, inside lower R, tilting angle, and section height) were analyzed by applying a Taguchi L18 design (2¹ × 3<SUP>6</SUP>). Design levels by design factor were determined referring to 5 existing ODHs. 18 ODHs developed in the study were relatively evaluated comparing with a reference ODH (0 point) through an 11-point bipolar scale (-5: extremely dissatisfaction, 0: no difference, +5: extremely satisfaction) by twenty participants aged 20s ~ 50s. Results: Section width and inside upper R were significant on satisfaction of ODH. Conclusion: A design guideline for ODH was established considering users’ satisfaction. Application: The design factor evaluation protocol using Taguchi method applied in the study can be applicable to the other vehicle moving handles (e.g., inside door handle, door trim grip handle, door trim pull handle).

Development of a Distributed Representative Human Model Generation and Analysis System for Multiple-Size Product Design

Baekhee Lee,Kihyo Jung,Heecheon You 대한인간공학회 2011 大韓人間工學會誌 Vol.30 No.5

Objective: The aim of this study is to develop a distributed representative human model(DRHM) generation and analysis system. Background: DRHMs are used for a product with multiple-size categories such as clothing and shoes. It is not easy for a product designer to explore an optimal sizing system by applying various distributed methods because of their complexity and time demand. Method: Studies related to DRHM generation were reviewed and the RHM generation interfaces of three digital human model simulation systems(Jack<SUP>®</SUP>, RAMSIS<SUP>®</SUP>, and CATIA Human<SUP>®</SUP>) were reviewed. Results: DRHM generation steps are implemented by providing sophisticated interfaces which offer various statistical techniques and visualization methods with ease. Conclusion: The DRHM system can analyze the multivariate accommodation percentage of a sizing system, provide body sizes of generated DRHMs, and visualize generated grids and DRHMs. Application: The DRHM generation and analysis system can be of great use to determine an optimal sizing system for a multiple-size product by comparing various sizing system candidates.

Development of a distributed representative human model generation and analysis system (DRHM-GAS): Application to optimization of flight suit and pilot oxygen mask sizing systems

Lee, Baekhee,Lee, Wonsup,Yang, Xiaopeng,Jung, Kihyo,You, Heecheon Elsevier 2019 International journal of industrial ergonomics Vol.72 No.-

<P><B>Abstract</B></P> <P>A computerized system is needed for effective determination of the sizing system of a multiple-size product. The present study developed a distributed representative human model generation and analysis system (DRHM-GAS) which can generate various sizing system candidates for a target population using different DRHM generation methods and evaluate the sizing system candidates. A five-step DRHM generation procedure (target population characterization, anthropometric variable selection, key dimension selection, grid formation, and DRHM size determination) was developed and implemented into the DRHM-GAS. A generated sizing system candidate is evaluated in the DRHM-GAS by a set of metrics including multivariate accommodation percentage and the number of sizing categories. The effectiveness of the DRHM-GAS was examined with two case studies of the development of optimal sizing systems for men's flight suit design based on the anthropometric data of US Army pilots and pilot oxygen mask design based on the facial anthropometric data of ROKAF pilots. The DRHM-GAS would be of use for product designers to establish an appropriate sizing system with efficiency.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A distributed representative human model generation and analysis system (DRHM-GAS) was developed. </LI> <LI> The DRHM-GAS can generate various sizing system candidates using different DRHM generation methods. </LI> <LI> The effectiveness of the DRHM-GAS was found effective to design an optimal sizing system for men's flight suit design. </LI> <LI> The DRHM-GAS enables a product designer to establish an optimal sizing system with efficiency. </LI> </UL> </P>

A 3D anthropometric sizing analysis system based on North American CAESAR 3D scan data for design of head wearable products

Lee, Wonsup,Lee, Baekhee,Yang, Xiaopeng,Jung, Hayoung,Bok, Ilgeun,Kim, Chulwoo,Kwon, Ochae,You, Heecheon Elsevier 2018 COMPUTERS & INDUSTRIAL ENGINEERING Vol.117 No.-

<P><B>Abstract</B></P> <P>The present study developed a sizing analysis system for head-related product designs based on the Civilian American and European Surface Anthropometry Resource (CAESAR) database of North Americans. A total of 2299 heads in the CAESAR database were manually edited and 26 anthropometric landmarks were marked on the edited 3D heads to measure 30 anthropometric dimensions related to head-related product designs. The 3D anthropometric sizing analysis system (3D-ASAS) developed in the study provides analysis functions of a sizing system and representative face models by considering a target product, a target population, the number of size categories, and key anthropometric dimensions based on the CAESAR head measurements. Further research to reduce the efforts of manual editing and landmarking of 3D body scan data is discussed for efficient application of the 3D-ASAS to the design process of various wearable products.</P> <P><B>Highlights</B></P> <P> <UL> <LI> 2299 heads of the Civilian American and European Surface Anthropometry Resource (CAESAR) were edited for measurement. </LI> <LI> 30 anthropometric head and face dimensions were measured. </LI> <LI> A 3D Anthropometric Sizing Analysis System (3D-ASAS) was developed and applied in head-wearable product design. </LI> <LI> A sizing system of a head-wearable product can be easily found by product designers through simple use of the 3D-ASAS. </LI> </UL> </P>

Ergonomic Evaluation of Console Chairs for a Weapon Locating Radar

Baekhee Lee,Kihyo Jung,Jineun Jeong,Jinman Kim,Wongi Hong,Seikwon Park,Heecheon You 대한인간공학회 2014 大韓人間工學會誌 Vol.33 No.2

Objective:The present study is intended to evaluate the usability of a console chair for a weapon locating radar by comparing with different kinds of chair design. Background: Console chairs need to be ergonomically designed to reduce physical workload of operators and improve mission capability; few studies have been reported which systematically evaluate usability of military console chairs. Method: Ergonomic design of a console chair, a bus seat, and an office chair was evaluated in terms of headrest, seatback, seatpan, armrest, and controller on a 7-point scale. Ten males in their 20s and 30s were recruited considering the demographic characteristics of console operators. Results: The satisfaction scores of the console chair for headrest, seatback, and seatpan were significantly higher than those of the bus seat (mean difference [MD] = 0.9) and office chair (MD = 1.3). Meanwhile, the satisfaction scores of the console chair for armrest and controller were significantly lower than those of the office chair (MD = -1.4) and bus seat (MD = -2.2). Conclusion: The armrest and controller of the console chair needs ergonomic improvements for better comfort. Application: The evaluation results of the console chair would be of use for ergonomic console chair design.

Evaluation of an Ergonomic Seat Motion System using EOG Analysis

Baekhee Lee,Jangwoon Park,Younggeun Choi,Jihyoung Lee,Taekho You,Hyewon Lee,Sungjin Sah,Heecheon You 대한인간공학회 2012 대한인간공학회 학술대회논문집 Vol.2012 No.11

Objective: The aim of this study is to develop and evaluate an ergonomic seat motion system for reducing driver’s mental fatigue. Background: Driving fatigues are physically and cognitively occurred due to internal/external workloads generated by various driving environments. In particular, passive task-related (PTR) fatigue occurred by monotonous driving (e.g., expressway driving) induces drowsy driving and reduces driving ability. Thus, seat motion systems (SMSs) for decreasing driver’s mental fatigue have been developed recently; however SMSs need those validations. Method: Three-step research protocol (S1. development of a SMS, S2. experiment on ergonomic driving, S3. evaluation of the SMS) was applied as followings; (1) development of the SMS derived from literature survey, (2) measurement of EOG signals through expressway driving simulation experiment (n = 30; 20s ~ 50s, driving experience > 2 yr) at both a static seat and a dynamic seat applied with the SMS, and (3) validation of the SMS through EOG waveform analysis. Meanwhile, the present study developed and applied an eye location correction algorithm to minimize variation of driver’s eye location by occurring seat motion. Results: Three eye blink types (alert, normal, drowsy) were classified through K-means clustering analysis by using three EOG parameters (peak amplitude, closing time, opening time). 70% of drivers had that drowsy blink rate at the dynamic seat was reduced comparing with that at the static seat. Mean drowsy blink rate at the dynamic seat (35%) was significantly lower than that at the static seat (38%) (z = 9.56, p < .001). Conclusion: The developed SMS can contribute to reducing driver’s PTR fatigue. Application: The SMS can be applied with real vehicles for maintaining driving ability and driving safety.

Development of a Screening Swallowing Algorithm for Using Ultrasonic Doppler Sensor and Microphone

Baekhee Lee,Giltae Yang,Sewon Hong,Duklyul Na,Heecheon You 대한인간공학회 2015 대한인간공학회 학술대회논문집 Vol.2015 No.10

Objective: The present study is to develop an algorithm for screening only swallowing movements out of various laryngopharyngeal movements using ultrasonic Doppler sensor and microphone. Background: Only swallowing movements need to be discriminated out of various laryngopharyngeal movements (e.g., vocalization, cough) measured by a swallowing measurement system using ultrasonic Doppler sensor for specialization in swallowing research. Method: laryngopharyngeal movement and audio signals during swallowing, cough, vocalization, respiratory, and neck movement were simultaneously measured three times to five healthy adults by ultrasonic Doppler sensor and microphone. A swallowing screening algorithm calculating movement-to-audio ratio applied with swallowing apnea was developed for screening only swallowing movements. Results: Vocalization, cough, and respiratory movements were perfectly discriminated with swallowing movements by the swallowing screening algorithm; however, neck rotation movements 73% due to occurring no laryngopharyngeal movements. Conclusion: The swallowing screening algorithm developed in the study could discriminate swallowing movements from vocalization, cough, and respiratory movements. Application: The swallowing screening algorithm can be applied to the swallowing measurement device and contribute to accurate evaluation of swallowing movements for patients with dysphagia.