Some discomforts have been considered normal for far too long. Pain that is accepted as an unavoidable part of the cycle, warning signs that are downplayed, and conversations about menstruation that are still surrounded by silence. This reflection gave rise to SISNA, the project developed by the Institut Escola del Treball de Barcelona and awarded the second of the two third prizes in the 5th edition of the VET Knowledge Transfer Awards, promoted by FPEmpresa and Grupo Esprinet.
The proposal begins with an everyday situation: a young woman experiences pain during menstruation, tries different products and wonders whether what she is experiencing should really be considered normal. From there, the team puts forward a central idea: women’s health still does not always receive the attention it deserves, and menstruation, far from being something to ignore or minimise, can provide useful information about the body.
“Something as natural as menstruation, an experience we all share, should not be ignored or minimised,” the team states in the project presentation video.
From this perspective, SISNA proposes a reusable menstrual cup with a sensory ring integrated into its base. Its purpose is not to provide a diagnosis, but to offer an early warning of possible alterations. The team explains it clearly: “SISNA does not replace a medical diagnosis; it simply enables prevention before a problem develops.”
From product design to prevention
The project began with an analysis of different menstrual cup models already available on the market. The students examined aspects such as sealing, anatomical adaptability and ease of removal, with the aim of designing an ergonomic and functional solution.
The cup was designed using SolidWorks, selecting a shape intended to be comfortable and adaptable. However, the project’s main innovation lies in the sensory ring integrated into its base, an additional element that does not interfere with the positioning or use of the cup but makes it possible to monitor menstrual pH.
The idea is based on a statement that captures the essence of the project: “Menstrual blood is not waste; it is information.” Through this approach, SISNA turns a menstrual hygiene product into a preventive monitoring tool.
The team explains that vaginal pH is usually between 3.8 and 4.5, an acidic environment that acts as a barrier against infections. During menstruation, this level may rise, but if it does not return to its usual values after the period, the change could act as a warning sign of a possible infection or irregularity.
To detect these variations, the project uses anthocyanins, a pigment found in red cabbage that changes colour depending on acidity levels. The outer layer of the ring allows menstrual plasma to pass through, while the inner hydrogel filters out solid components. When the plasma comes into contact with the indicator, a colour change occurs.
This colour variation works as a visual warning: intense red for a highly acidic environment, purple or violet for a more neutral level, and blue or green for greater alkalinity. In this way, the cup can provide a simple indication of possible changes in the body’s balance.
A reusable, accessible and sustainable solution
SISNA also incorporates environmental and social dimensions. The cup is designed to be made from medical-grade silicone, selected for its flexibility, durability and compatibility with the body. It can also be reused for years and withstand sterilisation processes, making it a long-lasting alternative to other menstrual products.
The sensory ring is designed to be renewed with each cycle. According to the team, washing the cup and ring with water and neutral soap restores the indicator to its original colour, allowing one ring to be used throughout a menstrual period and replaced with a new one the following month.
This long service life also connects the project with another objective: improving access to menstrual health solutions for women with fewer resources. As the team explains, “its long lifespan makes it accessible to women with limited financial resources.”
However, SISNA goes beyond proposing a product. It also opens up a conversation about how women’s health is researched and the need to pay greater attention to signs that have historically been understudied. The project highlights menstruation as a potential source of information and explores how technology can help interpret it in a simple, visual and non-invasive way.
“Because VET does not only create; it researches and transforms. And women are here to lead this change,” the team states at the end of its presentation.








