A framework for effective face-mask contact modeling based on finite element analysis for custom design of a facial mask

Abstract

A novel contact model is presented to efficiently solve a face-mask contact problem by using the finite element (FE) method for the optimized design of a custom facial mask. Simulation of contact pressure for various mask designs considering material properties of the face allows virtual evaluation of the suitability of a mask design for a person’s face without conducting empirical measurement of the face-mask contact pressure. The proposed contact model is accomplished by combining three approaches to reduce the calculation cost of simulating the face-mask contact: (1) use of a simplified and modifiable mask model that applies a spline curve to design points; (2) reduction of the FE model of the face by applying static condensation; and (3) application of a contact assumption that uses the Lagrange multiplier method. A numerical case study of a medical mask design showed that the proposed model could calculate the face-mask contact pressure efficiently (0.0448 sec per design). In a pilot usability experiment, the measured contact pressure was found similar values (range of mean contact pressure: 0.0093 ~ 0.0150 MPa) to the estimated values (range of mean contact pressure: 0.0097 ~ 0.0116 MPa).

Measuring Total Filtration Efficiency of Surgical and Community Face Masks: Impact of Mask Design Features

“…Most of 26 tested masks showed lower TFE values without the nosepiece, irrespectively of the outward flowrate. Indeed, the median [fist quartile; third quartile] values of TFE measured without nosepiece at the three flow rates were 12 [9,15] %, 21 [17,29] % and 32 [25,39] % respectively. With the nosepiece in place, the same group of masks tested in identical testing conditions presented TFE values of 15 [13,19] %, 28 [22,33] % and 40 [31,45] %.…”

“…Wang and Solano studied how leakages were linked to a wide variety of facial characteristics and mask designs using a 3D-scanning face model [37], [38]. Further studies on face mask fitting were also conducted with Finite Element Analysis and aimed at studying the contact pressure between mask and facial anatomy [39]. Additive manufacturing (AM) was investigated in silico by Carr et al as a mean to optimize fitting and reduce leakage, obtaining an effective sealing only by filling the gap between the mask and the face with an adaptable gasket added to the rigid AM materials [19].…”

The Influence of Head Strap Elasticity on the Protective Properties of Filtering Facepiece Respirators

“…Many scientific studies have been devoted to the improvement of filtering respirators. In particular, there have been proposed: a rational design of the perforated obturator (Cheberiachko et al, 2023), a production of filter respirator half-masks with a special frame (Cai et al, 2018), reinforcement of the obturator of the filtering respirator in the area of the nose with an additional seal (Kwon et al, 2022), application of sealants between a half mask and a face (Chopra et al, 2021;O'Kelly et al, 2022;Caggiari et al, 2022). Multiple use of respirators has been investigated (Małgorzata et al, 2023).…”

Increasing the Insulation Properties of Filter Respirators to Protect Miners’ Respiratory Organs From Dust

“…For example, one of the effective ways to solve this issue is to manufacture half-masks of a filtering respirator with a special frame, which, by changing its geometry, will retain the given shape of the front part of various types of users' faces and a sufficient area of the obturation line during conversations and head movements (Cai et al, 2018). Also, to increase the tightness of the half-mask to the user's face, the obturator of the filtering respirator in the area of nasal bridge is fully or partially reinforced with an additional sealant made of polyurethane foam, soft rubber or silicone (Kwon et al, 2022). Most manufacturers use a nose clip to reduce suction, especially around the nasal bridge.…”