Toward Mass Customization Through Additive Manufacturing: An Automated Design Pipeline for Respiratory Protective Equipment Validated Against 205 Faces
Respiratory protective equipment (RPE) is traditionally designed through anthropometric sizing to enable mass production. However, this can lead to long-standing problems of low-compliance, severe skin trauma, and higher fit test failure rates among certain demographic groups, particularly females and non-white ethnic groups. Additive manufacturing could be a viable solution to produce custom-fitted RPE, but the manual design process is time-consuming, cost-prohibitive and unscalable for mass customization. This paper proposes an automated design pipeline which generates the computer-aided design models of custom-fit RPE from unprocessed three-dimensional (3D) facial scans. The pipeline successfully processed 197 of 205 facial scans with <2 min/scan. The average and maximum geometric error of the mask were 0.62 mm and 2.03 mm, respectively. No statistically significant differences in mask fit were found between male and female, Asian and White, White and Others, Healthy and Overweight, Overweight and Obese, Middle age, and Senior groups.
1. Lan J, Song Z, Miao Z, et al., 2020, Skin Damage among Health Care Workers Managing Coronavirus Disease-2019. J Am Acad Dermatol, 82:1215-6.
2. Gefen A, Alves P, Ciprandi G, et al., 2020, Device-related Pressure Ulcers: SECURE Prevention. J Wound Care, 29:S1-52.
3. Gosch, M.E., Shaffer RE, Eagan AE, et al., 2013, B95: A New Respirator for Health Care Personnel. Am J Infect Control, 41:1224-30.
4. O’Kelly E, Arora A, Pirog S, et al., 2021, Comparing the Fit of N95, KN95, Surgical, and Cloth Face Masks and Assessing the Accuracy of Fit Checking. PLoS One, 16:e0245688. https://doi.org/10.1371/journal.pone.0245688
5. Pompeii LA, Kraft CS, Brownsword EA. et al. Training and Fit Testing of Health Care Personnel for Reusable Elastomeric Half-Mask Respirators Compared With Disposable N95 Respirators. JAMA, 323:1849-52. https://doi.org/10.1001/jama.2020.4806
6. Han DH, Choi KL, 2003, Facial Dimensions and Predictors of Fit for Half-mask Respirators in Koreans. Aiha J, 64:815-22. https://doi.org/10.1080/15428110308984877
7. McMahon E, Wada K, Dufresne A, 2008, Implementing Fit Testing for N95 Filtering Facepiece Respirators: Practical Information from a Large Cohort of Hospital Workers. Am J Infect Control, 36:298-300. https://doi.org/10.1016/j.ajic.2007.10.014
8. Ascott A, Crowest P, de Sausmarez E, et al., 2020, Respiratory Personal Protective Equipment for Healthcare Workers: Impact of Sex Differences on Respirator Fit Test Results. Br J Anaesth, 126:e48-e49. https://doi.org/10.1016/j.bja.2020.10.016
9. Regli A, Sommerfield A, von Ungernd.org/10.1 B, 2021, The Role of Fit Testing N95/FFP2/FFP3 Masks: A Narrative Review. Anaesthesia, 76:91-100. https://doi.org/10.1111/anae.15261
10. Lam S, Lee JK, Yau SY, et al., 2011, Sensitivity and Specificity of the User-seal-check in Determining the Fit of N95 Respirators. J Hosp Infect, 77:252-256. https://doi.org/10.1016/j.jhin.2010.09.034
11. Yu Y, Jiang L, Zhuang Z, et al. 2014, Fitting Characteristics of N95 Filtering-facepiece Respirators Used Widely in China. PLoS One, 9:e85299. https://doi.org/10.1371/journal.pone.0085299
12. Spies A, Wilson KS, Ferrie R, 2011, Respirator Fit of a Medium Mask on a Group of South Africans: A Cross sectional Study. Environ Health, 10:1-7. https://doi.org/10.1186/1476-069x-10-17
13. Wilkinson IJ, Pisaniello D, Ahmad J, et al., 2010, Evaluation of a Large-scale Quantitative Respirator-fit Testing Program for Healthcare Workers: Survey Results. Infect Control Hosp Epidemiol, 31:918-25. https://doi.org/10.1086/655460
14. Zhuang Z, Bergman M, Brochu E, et al., 2016, Temporal Changes in Filtering-facepiece Respirator Fit. J Occup Environ Hyg, 13:265-74.
15. Sandkovsky U, Schwedhelm M, Grayer S, et al., 2017, Small changes make a big difference in the fit of N95 respirators. Open Forum Infect Dis, 4:S166. https://doi.org/10.1093/ofid/ofx163.292
16. Roebuck JA, 1995, Anthropometric Methods: Designing to Fit the Human Body. In: Human Factors and Ergonomics Society. Santa Monica, California: Humanoid Factors and Ergonomics Society. https://doi.org/10.1177/106480469500300309
17. Pheasant S, 2014, Bodyspace: Anthropometry, Ergonomics and the Design of Work: Anthropometry, Ergonomics and the Design of Work. Boca Raton, Florida: CRC Press. https://doi.org/10.1201/9781482272420
18. Chen W, Zhuang Z, Benson S, et al., 2009, New Respirator Fit Test Panels Representing the Current Chinese Civilian Workers. Ann Occup Hyg, 53:297-305. https://doi.org/10.1093/annhyg/men089
19. Hack A, Hyatt EC, Held BJ, et al., 1973, Selection of Respirator Test Panels Representative of US Adult Facial Sizes. New Mexico: Los Alamos Scientific Lab., N. Mex, (USA). https://doi.org/10.2172/4335046
20. Zhuang Z, Bradtmiller B, 2005, Head-and-Face Anthropometric Survey of US Respirator Users. J Occup Environ Hyg, 2:567-576. https://doi.org/10.1080/15459620500324727
21. Zhuang Z, Landsittel D, Benson S, et al., 2010, Facial Anthropometric Differences among Gender, Ethnicity, and Age Groups. Ann Occup Hyg, 54:391-402.
22. Kim H, Han DH, Roh YM, et al., 2003, Facial Anthropometric Dimensions of Koreans and their Associations with Fit of Quarter-mask Respirators. Ind Health, 41:8-18. https://doi.org/10.2486/indhealth.41.8
23. Du L, Zhuang Z, Guan H, et al., 2008, Head-and-face Anthropometric Survey of Chinese Workers. Ann Occup Hyg, 52:773-782.
24. Yang L, Shen H, Wu G, 2007, Racial Differences in Respirator Fit Testing: A Pilot Study of Whether American Fit Panels are Representative of Chinese Faces. Ann Occup Hyg, 51:415-421. https://doi.org/10.1093/annhyg/mem005
25. Tuck CJ, Hague RJ, Ruffo M, et al., 2008, Rapid Manufacturing Facilitated Customization. Int J Comput Integr Manufact, 21:245-258. https://doi.org/10.1080/09511920701216238
26. Tan HW, An J, Chua CK, et al., 2019, Metallic Nanoparticle Inks 3D Printing of Electronics. Adv Electron Mater, 5:1800831. https://doi.org/10.1002/aelm.201800831
27. Choong YY, Maleksaeedi S, Eng H, et al., 2020, High Speed 4D Printing of Shape Memory Polymers with Nanosilica. Appl Mater Today, 18:100515. https://doi.org/10.1016/j.apmt.2019.100515
28. Tan HW, Saengchairat N, Goh GL, et al., 2020, Induction Sintering of Silver Nanoparticle Inks on Polyimide Substrates. Adv Mater Technol, 5:1900897. https://doi.org/10.1002/admt.201900897
29. Ng WL, Chua CK, Shen YF, 2019, Print me an Organ! Why we are not there yet. Prog Polym Sci, 97:101145. https://doi.org/10.1016/j.progpolymsci.2019.101145
30. Bibb R, Eggbeer D, Evans P, 2010, Rapid Prototyping Technologies in Soft Tissue Facial Prosthetics: Current State of the Art. Rapid Prototyp J, 16:25852. https://doi.org/10.1108/13552541011025852
31. Eggbeer D, Evans PL, Bibb R, 2006, A Pilot Study in the Application of Texture Relief for Digitally Designed Facial Prostheses. Proc Inst Mech Eng Part H, 220:705-14. https://doi.org/10.1243/09544119jeim38
32. Kai CC, Meng CS, Ching LS, et al., 2000, Facial prosthetic model fabrication using rapid prototyping tools. Integr Manuf Syst, 11:42-53. https://doi.org/10.1108/09576060010303668
33. Pallari J, Dalgarno K, Munguia J, et al. 2010, Design and Additive Fabrication of Foot and Ankle-foot Orthoses. In: Proceedings of the 21st Annual International Solid Freeform Fabrication Symposium an Additive Manufacturing Conference. https://doi.org/10.32656/2018_29sff_symposium
34. Pallari JH, Dalgarno KW, Woodburn J, 2001, Mass Customization of Foot Orthoses for Rheumatoid Arthritis Using Selective Laser Sintering. IEEE Trans Biomed Eng, 57:1750-6. https://doi.org/10.1109/tbme.2010.2044178
35. Eggbeer D, Bibb R, Williams R, 2005, The Computer-aided Design and Rapid Prototyping Fabrication of Removable Partial Denture Frameworks. Proc Inst Mech Eng Part H, 219:195-202. https://doi.org/10.1243/095441105x9372
36. Salles AS, Gyi DE, 2013, Delivering Personalised Insoles to the High Street Using Additive Manufacturing. Int J Comput Integr Manuf, 2013. 26:386-400. https://doi.org/10.1080/0951192x.2012.717721
37. Salles AS, Gyi DE, 2012, The Specification of Personalised Insoles Using Additive Manufacturing. Work, 41:1771-4. https://doi.org/10.3233/wor-2012-0383-1771
38. Wu YY, Acharya D, Xu C, et al., 2018, Custom-Fit Three dimensional- printed BiPAP Mask to Improve Compliance in Patients Requiring Long-term Noninvasive Ventilatory Support. J Med Dev, 12:0310031-8. https://doi.org/10.1115/1.4040187
39. Ma Z, Hyde P, Drinnan M, et al., 2021, Custom Three-Dimensional-Printed CPAP Mask Development, Preliminary Comfort and Fit Evaluation. J Med Dev, 15:024501. https://doi.org/10.1115/1.4050201
40. Martelly E, Rana S, Shimada K, 2021, Design and Fabrication of Custom-Fit BiPAP and CPAP Masks Using Three-Dimensional Imaging and Three-Dimensional Printing Techniques. J Med Dev, 15:024502. https://doi.org/10.1115/1.4049981
41. Cai M, Li H, Shen S, et al., 2018, Customized Design and 3D Printing of Face Seal for an N95 Filtering Facepiece Respirator. J Occup Environ Hyg, 15:226-34. https://doi.org/10.1080/15459624.2017.1411598
42. Finne H, Liacouras P, Wilsnack AR, et al., Custom Fit N95 Respirator Acceptability and Fit. Bethesda, Maryland, United States: Walter Reed National Military Medical Center.
43. Stokes AA, 2021, 3DPPE: Rapid 3D Printing of Personalised Protective Facemasks and Visors to WHO Standard for Healthcare Workers Treating SARS-CoV-2 Patients.
44. Choong YY, Tan HW, Patel DC, et al., 2002, The Global Rise of 3D Printing during the COVID-19 Pandemic. Nat Rev Mater, 5:637-639. https://doi.org/10.1038/s41578-020-00234-3
45. Sherborne C, Claeyssens F, 2021, Considerations Using Additive Manufacture of Emulsion Inks to Produce Respiratory Protective Filters against Viral Respiratory Tract Infections Such as the COVID-19 Virus. Int J Bioprint, 7:316. https://doi.org/10.18063/ijb.v7i1.316
46. Shpichka A, et al., 2020, Engineering a Model to Study Viral Infections: Bioprinting, Microfluidics, and Organoids to Defeat Coronavirus Disease 2019 (COVID-19). Int J Bioprint, 6:302. https://doi.org/10.18063/ijb.v6i4.302
47. Bishop EG, Leigh SJ, 2020, Using Large-scale Additive Manufacturing as a Bridge Manufacturing Process in Response to Shortages in Personal Protective Equipment during the COVID-19 Outbreak. Int J Bioprint, 6:281. https://doi.org/10.18063/ijb.v6i4.281
48. Celik HK, Kose O, Ulmeanu ME, et al., 2020, Design and Additive Manufacturing of Medical Face Shield for Healthcare Workers Battling Coronavirus (COVID-19). Int J Bioprint, 6:286. https://doi.org/10.18063/ijb.v6i4.286
49. Flanagan ST, Ballard DH, 2020, 3D Printed Face Shields: A Community Response to the COVID-19 Global Pandemic. Acad Radiol, 27:905. https://doi.org/10.1016/j.acra.2020.04.020
50. Wesemann C, Pieralli S, Fretwurst T, et al., 2020, 3-d Printed Protective Equipment during covid-19 Pandemic. Materials, 13:1997. https://doi.org/10.3390/ma13081997
51. Cavallo L, Marcianò A, Cicciù M, et al., 2020, 3D Printing beyond Dentistry during COVID 19 Epidemic: A Technical Note for Producing Connectors to Breathing Devices. Prosthesis, 2:46-52. https://doi.org/10.3390/prosthesis2020005
52. Clifton W, Damon A, Martin AK, 2020, Considerations and Cautions for Three-Dimensional-Printed Personal Protective Equipment in the COVID-19 Crisis. 3D Print Addit Manuf, 7:97-9. https://doi.org/10.1089/3dp.2020.0101
53. Novak JI, Loy J, 2020, A Critical Review of Initial 3D Printed Products Responding to COVID-19 Health and Supply Chain Challenges. Emerald Open Res, 2:24. https://doi.org/10.35241/emeraldopenres.13697.1
54. Swennen GR, Pottel L, Haers PE, 2020, Custom-made 3D-printed Face Masks in Case of Pandemic Crisis Situations with a Lack of Commercially Available FFP2/3 Masks. Int J Oral Maxillofac Surg, 49:673-7. https://doi.org/10.1016/j.ijom.2020.03.015
55. Novak JI, Loy J, 2020, A Quantitative Analysis of 3D Printed Face Shields and Masks during COVID-19. Emerald Open Res, 2:42. https://doi.org/10.35241/emeraldopenres.13815.1
56. Provenzano D, Rao YJ, Mitic K, et al., 2020, Rapid Prototyping of Reusable 3D-printed N95 Equivalent Respirators at the George Washington University. Preprints, 2020:2020030444. https://doi.org/10.20944/preprints202003.0444.v1
57. Greig P, Carvalho C, El-Boghdadly K, et al., 2020, Safety Testing Improvised COVIDng IPersonal Protective Equipment Based on a Modified Full‐odifiSnorkel Mask. Anaesthesia, 75:970-1. https://doi.org/10.1111/anae.15085
58. Rogers B, Bosker GW, Crawford RH, et al., 2007, Advanced Trans-tibial Socket Fabrication Using Selective Laser Sintering. Prosthet Orthot Int, 31:88-100. https://doi.org/10.1080/03093640600983923
59. Schrank ES, 2011, Dimensional Accuracy of Ankle-Foot Orthoses Constructed by Rapid Customization and Manufacturing Framework. J Rehabil Res Dev, 48:31. https://doi.org/10.1682/jrrd.2009.12.0195
60. Paterson AM, Donnison E, Bibb RJ, et al., 2014, Computer aided Design to Support Fabrication of Wrist Splints Using 3D Printing: A Feasibility Study. Hand Ther, 19:102-13. https://doi.org/10.1177/1758998314544802
61. Cazon A, Aizpurua J, Paterson A, et al., 2014, Customised Design and Manufacture of Protective Face Masks Combining a Practitioner-friendly Modelling Approach and Low-cost Devices for Digitising and Additive Manufacturing: This Paper Analyses the Viability of Replacing Conventional Practice with AM Method to Make Customized Protective Face Masks. Virtual Phys Prototyp, 9:251-261. https://doi.org/10.1080/17452759.2014.958648
62. Ellena T, Mustafa H, Subic A, et al., 2018, A Design Framework for the Mass Customisation of Custom-fit Bicycle Helmet Models. Int J Ind Ergon, 64:122-33. https://doi.org/10.1016/j.ergon.2018.01.005
63. Galvez A, Iglesias A, Puig-Pey J, 2012, Iterative Two-step Genetic-algorithm-Based Method for Efficient Polynomial B-spline Surface Reconstruction. Inf Sci, 182:56-76. https://doi.org/10.1016/j.ins.2010.09.031
64. Sela M, Toledo N, Honen Y, et al., 2016, Customized Facial Constant Positive Air Pressure (CPAP) Masks. arXiv, 2016:07049.
65. Li S, Waheed U, Bahshwan M, et al., 2021, A Scalable Mass Customisation Design Process for 3D-printed Respirator Mask to Combat COVID-19. Rapid Prototyp J, 27:1302-17. https://doi.org/10.1108/rpj-10-2020-0231
66. Mensura M, 2020, Mensura Mask Website. Available from: Available from: https://www.mensuramask.com [Last accessed on 2021 Feb 04].
67. BBC, 2020, What is it Like to Wear a Customised Face Mask? Available from: https://www.bbc.co.uk/programmes/p08ky38x [Last accessed on 2021 Feb 04].
68. Mensura M, 2020, How to Perform a Face Scan. Available from: https://www.mensuramask.com/instructions [Last accessed on 2021 Jun 26].
69. Mensura M, 2020, Participate in the Study. Available from: https://imperial.eu.qualtrics.com/jfe/form/SV_8jC7fcmYEOT6aMt [Last accessed on 2021 Jun 26].
70. Yianilos PN, 1993, Data Structures and Algorithms for Nearest Neighbor Search in General Metric Spaces. In: Proceedings of the fourth annual ACM-SIAM Symposium on Discrete algorithms.
71. Bentley, J.L., 1975, Multidimensional Binary Search Trees Used for Associative Searching. Commun ACM, 18:509-517. https://doi.org/10.1145/361002.361007
72. Richard MJ, Morris C, Deen BF, et al., 2009, Analysis of the Anatomic Changes of the Aging Facial Skeleton Using Computer-assisted Tomography. Ophthalmic Plast Reconstr Surg, 25:382-386. https://doi.org/10.1097/iop.0b013e3181b2f766
73. Kahn DM, Shaw RB Jr., 2008, Aging of the Bony Orbit: A Three-dimensional Computed Tomographic Study. Aesthet Surg J, 28:258-64.
74. Mendelson BC, Hartley W, Scott M, et al., 2007, Age-related Changes of the Orbit and Midcheek and the Implications for Facial Rejuvenation. Aesthet Plast Surg, 31:419-423. https://doi.org/10.1007/s00266-006-0120-x
75. Zadoo VP, Pessa JE, 2000, Biological Arches and Changes to the Curvilinear form of the aging Maxilla. Plast Reconstr Surg, 106:460-6. https://doi.org/10.1097/00006534-200008000-00036
76. World Health Organization. Body Mass Index BMI. Available from: https://www.euro.who.int/en/health-topics/diseaseprevention/nutrition/a-healthy-lifestyle/body-mass-indexbmi [Last accessed on 2021 Fe b 04]. https://doi.org/10.1007/springerreference_179795
77. Lee W, Kim H, Jung D, et al., 2013, Ergonomic Design and Evaluation of a Pilot Oxygen Mask. In Proceedings of the Human Factors and Ergonomics Society Annual Meeting. Los Angeles, CA: SAGE Publications Sage CA. https://doi.org/10.1177/1541931213571371
78. Lee W, Jung D, Park S, et al., 2012, Development of a Methodology to Design a Pilot Oxygen Mask Based on Virtual Fit Testing Method. In: Proceedings of the 2012 Spring Conference of the Korean Institute of Industrial Engineers.