Understanding Female Breast Shape to Improve Bra Sizing Via 3D and 4D Body Scanning Technology

Abstract

Due to the limitation of traditional linear body measurements in representing the complicated three-dimensional (3D) shape of female breast, in this dissertation, alternative methods to study breast shape for product development were explored. In two-dimension (2D), topographic contour maps were created and an Asymmetry Index was proposed to quantify the degree of asymmetry between the left and right breasts. This 2D system was used in the aesthetic evaluation of nude breast and the shaping effects of structured-bras and soft-bras. In 3D, two methods of handling 3D body scans were proposed, which capture data throughout the surface of the scan systematically. Both the 2D and 3D systems eliminate the need of palpation to find anatomical body landmarks, on which the accuracy of traditional measurements depend. In four-dimension (4D), 4D body scanning technology was introduced to quantitively study breast shape under motion. Moreover, while the information of the upper boundary of the breasts is missing on 3D scans, it can be retrieved with the help of 4D scanning, by taking advantage of the time delay in the vertical displacement between the breasts and the chest wall during physical activity. This method is essential for the accurate separation of the breasts: to acquire critical anthropometric measurements such as breast volume, and to make complete the 3D breast-shape evaluation system. Product development of bras still relies on human fit models. Aggregate-fit-loss is a concept attempting to estimate the accumulative fit-loss, resulting from the body-shape discrepancy, between the fit models and individual consumers. Based on the 3D evaluation system, a feasible solution to optimize the sizing system of bras was proposed, to minimize the aggregate-fit-loss by shape categorization and optimized selection of fit models. For the industry, the method overcomes the challenge of finding ideal fit models, filling the lack of a reliable selection criteria. For consumers, technological solutions were also presented for finding their shape-based selection of products that may best fit them. With 3D scanner becoming more accessible and the development of cellphone scanning, methods presented in this dissertation might bring revolutionary changes in apparel sizing and how bra products are made.