FACE
SCAN

TRIX Connections and CIIRC CTU have developed a face scanning application to better adapt the RP95 protective half mask.

The Czech Institute of Informatics, Robotics and Cybernetics of the Czech Technical University in Prague (CIIRC CTU) and TRIX Connections, a start-up and spin-off company at the Czech Technical University in Prague, jointly developed software for smartphones that recommends a suitable seal size for more comfortable use of the RP95 protective half mask. Customization and connection of end users directly with manufacturers is the essence of distributed production, which research at CIIRC CTU has long been concerned with. The application is launched just a few days after the CIIRC CTU team received an extraordinary “Czech Head” Award from the Council for Research, Development and Innovation for their mask for 3D printing.

The CIIRC RP95-3D protective half mask was developed during a single week of March in response to the lack of personal protective equipment in the first coronavirus crisis. In the summer of 2020, the mask underwent complete testing and obtained full EU certification according to the relevant standards for personal protective equipment, which allows the CE marking. In parallel, the RP95-M mask model was developed for mass production by plastic injection molding. This is produced on the basis of a license by a consortium of companies led by CARDAM.

According to the test results, the effectiveness of the half mask is higher in comparison with standard FFP3 respirators, which are in the same safety class. Adequate sealing on the face is a prerequisite for safety. At the same time, the comfort of wearing the mask is also important. “Previous mask and seal models have a uniform size to fit most human faces. However, it does not necessarily provide the most comfortable solution for everyone,” Dr. Petr Kadera (CIIRC CTU) specifies.

This is what became the task for the further joint development of TRIX Connections and CIIRC CTU, which is also becoming an example of a customized solution for production. Support for the digitization of production is one of the goals of the European Institute of Innovation and Technology, EIT Manufacturing, which is why this project was supported by EIT Manufacturing this year as part of its calls.

Development teams coordinated by TRIX Connections focused on how to ensure that the half mask was as adaptable as possible and as easy as possible to the needs of individual users. They decided to use modern digital technologies that are already commonly available. This requirement is met by new models of mobile devices that are equipped with depth cameras (TrueDepth Camera) for face recognition and augmented reality applications (such as newer Apple devices).

These technologies make it possible to obtain a 3D image of a human face and analyze its basic parameters for further use. It was also necessary to determine which seal sizes would best cover the entire population. To make this possible, a wide range of facial topology data had to be processed. TRIX Connections therefore commissioned the Institute of Anthropology of Masaryk University to process a library of facial topological data. Faces with similar patterns were grouped into three classes for the adult population. Masaryk University used its database for this classification and analyzed a set of facial models of 500 volunteers, men and women aged 18–84.

Based on this, a data model was created first, followed by a physical model of an averaged human face and other facial models, which together cover the main characteristics of the Czech adult population. The interactions of the half-mask and face seals were modeled, resulting in a total of three seal sizes, for which the average distance between the nose and chin is essential. Thus, the main parameters for the development of an application for 3D facial scanning were determined. The application is freely accessible in the App Store under the name “Mask Creator”.