# Design and Evaluation of Masteromy Bras Using 3D Virtual Prototyping
## 2 Methodology
### Bra Design Developments  
#### 2.2.1 Model Details  
Two different mastectomy bra models with external prosthesis were designed to meet the needs of women who have undergone unilateral mastectomy. The designs were developed to highlight two different approaches in mastectomy bra design: the \"sexy\" and \"comfort\" design approaches. By \"sexy\", we aimed to represent aesthetic and elegant design-focused approaches, while \"comfort\" was used to emphasize functionality, comfort, and suitability for sensitive skin. These models prioritize functionality and user comfort while incorporating aesthetic elements to create a balance between practical needs and visual appeal. The goal was to facilitate the daily lives of post-mastectomy users and enhance their confidence by helping them feel attractive. The 2D technical drawings of the developed models were created using Adobe Illustrator software and are presented in Figure 2. The detailed design features of the mastectomy bras are described below. Figure 3 illustrates the stitching details and prosthesis pocket placement of the interior part of Model 1 and Model 2. Model 1: Sexy  
Model 1 was designed with a \"sexy\" aesthetic approach to meet both functional and aesthetic needs, particularly for women with surgical scars in the lower breast area. The double-panel cup structure ensures breast tissue support and prosthesis stability, providing anti-gravity functionality and preventing slippage. To enhance comfort, the design is wire-free, featuring a 3D cup structure and vertical side partitions that minimize irritation on scar tissue. However, the absence of underwire can cause flattening of the lower cup, \begin{table}
\begin{tabular}{c c c} \hline
**Design Criterion** & **Requirement** & **Design Solution** \\ \hline \multirow{4}{*}{Prosthesis Stability and Movement Control} & Preventing imbalanced movements between prosthesis and natural breast during physical activities [16] & Using a wide wing design to stabilize the prosthesis and minimize movement during physical activities [39] \\ \cline{2-3}  & Improving prosthesis stability within the bra to prevent displacement [16] & Designing wide shoulder straps to evenly distribute prosthesis weight and reduce pressure on shoulders [41] \\ \hline \multirow{4}{*}{Aesthetic and Functional Integration} & Addressing the lack of vibrant colors to meet user expectations [30; 31] & Adding vibrant color options to expand product variety and better meet aesthetic preferences \\ \cline{2-3}  & Enhancing accessory details to improve aesthetic appeal [30; 31] & Introducing decorative elements like lace, trims, or modern features to align with user preferences \\ \cline{2-3}  & Preventing difficulties in wearing and removing for users with lymphedema, arthritis, limited mobility, or post-surgery sensitivity [39] & Utilizing alternative closure mechanisms such as zippers and buttons to improve usability and provide customization for diverse user needs \\ \hline \end{tabular}
\end{table} 
Table 1: _Cont._  
Figure 2: Technical drawing of the developed models. reducing the stability of the prosthesis or natural breast. To address this, the lower cup was divided into sections to create a 3D structure, while a vertical partition was added to the side of the cup to function like an underwire, supporting the breast shape. In order to increase the stability of the prosthesis during virtual wear trials, the front, cup, and wing height of the bra were slightly increased and the prosthesis was completely covered by the bra. Wide, adjustable shoulder straps distribute weight evenly, reducing pressure on the shoulders and back, as recommended in the literature [37]. The optimized wing width securely holds the prosthesis in place without causing discomfort, while a three-row hook-and-eye closure offers adjustability for different body sizes. Minimal seams reduce irritation, and optional prosthesis pockets allow flexibility for unilateral use.