Antropometric Research on the Sizing of the MBU-20/P Aircrew Oxygen Mask

Abstract

Public reporting burden for this collection of infomnation is estimated to average 1 hour per response, Including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information, including suggestions for reducing this burden, to Washington Headquarters Services, Directorate for Information Operations and Reports, 1215 Jefferson Davis Highway, Suite 1204 The goal of this study was to determine sizing recommendation to improve the fit of the MBU-20/P Advanced Aircrew Oxygen Mask (AAOM). The approach was to do a fit test of the mask using flie current sizes and the latest anthropometric measuring technology, then analyze the differences between subjects who passed and those who failed. This was done in conjunction with an effort to develop a customization process method for the soft rubber portion of the mask. This sizing study concentrates on improving the fit of the hard shell. The sizes currently available are SN (Small Narrow), MN (Medium Narrow), MW (Medium Wide), and LW (Large Wide). While it was hypothesized at the outset that the fit could be improved by adding a size, the fit results indicated that this was not the case. Instead, the location of the mask with respect to the face seemed to be an overriding factor. SUBJECT TERMSSizing, Fit, Oxygen mask, Anthropometry EXECUTIVE SUMMARYThe goal of this study was to determine sizing recommendations to improve the fit of the MBU-20/P Advanced Aircrew Oxygen Mask (AAOM). Quality of fit is related to factors such as anthropometry, performance, and personal preference. Performance must be considered, because the quality of fit can change with usage. A mask with a good seal on the ground may break seal at high g. This is not an acceptable fit, so the size of the mask must be modified. Furthermore, some people are more tolerant of discomfort than others. A mask designed for two people with the same facial anatomy may be tolerable to one person and uncomfortable to another. An uncomfortable mask is a safety risk, so its size must be modified. What do you do when your suit doesn't fit? You take it to a tailor to have its size altered. Essentially, you have conducted your own fit test and have determined that the size is not right. When we see a lot of the same problems with fit, it is natural to want to know why the problem is there and what to do to fix it Understanding the relationship of anthropometry to an acceptable quality of fit is key to making recommendations reqarding sizing. Fit testing is a method conmionly used to take anthropometry, performance, and personal preference into account when making sizing recommendations. As such, our approach was to do a fit test of the AAOM mask using the current sizes and analyze the difference between subjects who passed die fit test and those who failed.Thirty male and Uiirty female subjects were tested. The subje...

Ergonomic Design and Evaluation of a Pilot Oxygen Mask

“…Previous research on a respirator design used representative face models; however, those respirators didn't consider the facial characteristics of statistically significant amount of a target population in their research. Yatapanage and Post (1992), Gross et al (1997), Han and Choi (2003), Han et al (2004), and Song and Yang (2010) proposed respirator design methods based on an average face size or 1 ~ 3 of representative face models. However, the previous study didn't explain details of the respirator design method based on the 3D facial data.…”

Ergonomic Design and Evaluation of a Pilot Oxygen Mask for Korea Air Force Pilots

“…An oxygen mask is required to be designed to properly fit the face of a target population to prevent users from the harmful atmosphere. The MBU-20/P (Gentex Corporation, U.S.A.) pilot oxygen mask, frequently used for the Korean Air Force (KAF) pilots, was originally designed using face anthropometric data of 2420 U.S. Air Force (USAF) personnel collected by Churchill et al [1] and had been improved by applying the three-dimensional face scan data of 60 (30 males and 30 females) pilots [2]. A survey conducted by Lee et al [3,4] on the usability evaluation of the MBU-20/P mask identified that more than 60 percent of KAF pilots suffered from excessive pressure and/or oxygen leakage around the nasal root due to the lack of fit from the oxygen mask to the face, which is most likely caused by a significant difference in facial shape and size between KAF pilots and USAF personnel [5].…”

“…Previous research on a mask design used representative face models; however, those masks didn't consider the facial characteristics analyzed to a significant amount of a target population in their research. Yatapanage and Post [6], Gross et al [2], Han and Choi [7], Han et al [8], and Song and Yang [9] proposed mask design methods based on an average face size or 1 ~ 3 of representative face models. However, the previous study didn't explain details of the mask design method based on the 3D facial data.…”

Analysis of the Facial Anthropometric Data of Korean Pilots for Oxygen Mask Design

“…The pilot oxygen mask is a half-face type mask covering the nasal area and mouth which stably supplies oxygen to a pilot at high altitude (Alexander et al, 1979). MBU-20/P (Gentex Corporation, USA) was initially designed based on US Air Force anthropometric survey data (Churchill et al, 1977), and then its size and shape were modified based on 3D facial scans data of 30 male and 30 female pilots (Gross et al, 1997). The questionnaire about the usability of pilots' equipment which was conducted by the Republic of Korea Air Force in 2006 reported that MBU-20/P causes excessive pressure or oxygen leakage at the nasal area of Korean pilots.…”

“…The mask is designed based on facial anthropometric data, but there is a lack of understanding of Korean pilots' distinguishing facial characteristics. Previous researchers (Han et al, 2004;Gross et al, 1997;Hack & McConville, 1978;Young, 1966) designed half-face masks based on the facial dimensions such as face length, lower face length, face width, nose length, nose width, nose protrusion, lip width, and bitragion-subnasale arc. Hack & McConville (1978) and Young (1966) suggested using a nasal dimensions (e.g., nasal root breadth, maximum nasal bridge breadth, nasal bridgementon length, nasal bridge-chin length) to design the shape of the nose part of the half-face mask.…”