Redesigning N95 Respirators

Improving the comfort and adjustability of current respirators

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The N95 respirator is the most common of the seven types of particulate-filtering facepiece dust masks. Based on the working environment and purpose (especially after the outbreak of Covid 19 pandemic), N95 respirators usually need to be worn for a long time, which requests the comfortable use of straps and masks.


According to Amazon reviews, one-size-fits-all masks and straps cause discomfort. Thus, this project aimed to propose a new design of N95 respirators to improve the comfort and adjustability of current respirators and accommodate as many ANSUR II population as possible.


To design a more comfortable and adjustable respirator, this project first employed a within-subject experiment to measure related anthropometric variables and subjective ratings of participants on existing respirators. We then used regression analysis to calculate design parameters.

The design parameters include mask width, mask breadth, top headband length & adjustability, and bottom headband length & adjustability.

Research methods

  • Within-subject experiment

  • Regression analysis

My Role

  • Conducted the whole project with other team members

  • Research plan creation

  • Data collection

  • Data analysis

  • Report writing


  • Overall: 4 weeks

Research Process

Project:  Redesigning Existing N95 Respirators

Design parameters

  • Mask width​

  • Mask breadth​

  • Top headband length & adjustability​

  • Bottom headband length & adjustability

  3 types of masks used in our experiment

3 types of masks used in our experiment


Within-subject experiment:

Participants (8 females, 10 males)

  • Step 1.  Measure 4 anthropometric variables

  • Step 2.  Ask participants to wear 3 types of masks and measure  their preferred headband length

  • Step 3.  Each participant performs three tasks wearing each mask: normal breathing, deep breathing, turning head

  • Step 4.  Each participant completes a questionnaire  asking comfort level of each mask 

Statistical analysis

  • Two parts: Headband length and Mask shell dimensions

    1.Headband length (& adjustability):

  • Fit regression models of:

  • Top headband length <-- Head circumference + BMI

  • Bottom headband length <-- Neck circumference + BMI

    2.Mask shell dimensions:

  • Fit a regression model of the subject's comfort score to determine the significantly influential factors of comfort

  • Calculate the sensitivity of each individual based on comfort scores

  • Use bivariate accommodation to design masks with 3 different sizes

Project:  Redesigning Existing N95 Respirators


  • Designed the different top band and bottom band for males and females separately based on linear regression models

  • Designed three different sizes for the mask's width and length (unisex design)

Thank you for reading my project!

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