2009 Volume 8 Issue 4 Pages 1011-1020
Through this research, I intend to show how improving the fit of a mask can benefit sufferers of hay fever. Currently available masks absorbed a large amount of pollen during experiments. However, the effects of wearing these masks are unclear. Therefore, I am interested in the fit of masks on faces. For quantitatively evaluating the fit ability of a mask on a face, I developed a device that measures the strain behavior of sheets and faces at the time of wearing a mask. To investigate the fit ability, angle change and position change at the time of vowel pronunciation were measured using the developed device comprising two shape sensors and a digital video camera. There were five measurement points on both the mask and face: two points ‘nc’ and ‘ns’ on the nose, one point ‘cc’ on the cheek and two points ‘jc’ and ‘js’ on the jaw. The first letters ‘n’, ‘c’ and ‘j’ denote the nose, cheek and jaw, respectively. The second letters ‘c’ and ‘s’ denote the centre and side, respectively. Four types of masks made of different materials and of different shapes were adopted as experiment samples: a 2D gauze mask, 3D gauze mask, pleated non-woven mask and molded non-woven mask. The subjects were seven young women. The fit ability of a mask was studied from the viewpoints of angular differences and correlation coefficients between a mask and a face, and the distance between the mask and face was measured. Analysis of angle changes showed that at point ns, the gauze masks assumed a convex shape against the face. The correspondence between results obtained for the gauze masks was lower at points ns, jc and js, whereas that for the non-woven masks was higher at points nc and cc. Moreover, analysis of the position changes revealed that the maximum vertical distances of the gauze masks were larger at points jc and js. These results proved that different materials and shapes of a mask yield different fit abilities.