PROPE Visor

Inspiration

The demand for the Personal Protective Equipment (PPE) for medical professionals and health care workers are at large ever since the virus broke out and the manufacturers are scrambling to meet the demands. Provided this situation, many hospitals and healthcare centers have started to use whatever they find to protect themselves while treating the patients. There was a big spur in the maker's community to make it easy for the manufacturers and supplement the demands by manufacturing face visors, masks, etc, thanks to the application of 3D printing. Our team started making 3D printed face visor head bands on request from the regional government that has been distributed to nearby hospitals and healthcare centers. But we felt that it wasn't enough to protect them well from the utmost exposure to virus in long-term and it's not fair for the very people who are in the frontline of the defense to be unprotected. So we decided to adapt our knowledge and experience from building a cleanroom for qualifying the bioburden of space instruments to a miniaturized version that can serve as a cleanroom around the face called PROPE (Pressure Optimized ProtectivE) Visor.

What it does

Similar to a Positive Air Pressure Respirator (PAPR) unit, a static positive air pressure is applied from the top of the head downwards through a H13 HEPA filter (<0.3 um particles with atleast 99.95% efficiency). H13 HEPA filter is better than the clinically widely used N95, FFP2 or FFP3 respirators. Alternatively automobile engine oil filter or vacuum bag filter can be used. PROPE Visor is a low-cost, relatively passive in terms of energy consumption and mechanisms, and easy to 3D print and build the assembly.

How I built it

The positive air pressure is created with the help of a static pressure fan from Noctua, with a flow rate of atleast 6 CFM that is typical in PAPR units. The positive static pressure air is forced through a H13 HEPA filter and allowed to flow around the the head surrounded by a head band holding the acrylic sheet as the wall of the visor. The acrylic sheet runs down until the shoulders at about 10 cm away from the face and back of the head similarly. This facilitates a continuous and smooth air flow around the head thus maintaining the environment surrounding the face clean. After each use of the PROPE Visor, the 3D printed parts can be cleaned with alcohol wipes or soap and the acrylic sheets are disposed. The AA batteries that powers the fan can also be replaced once it is depleted.

Challenges I ran into

During the initial CAD design and 3D printing for the demonstration version, the different parts were assembled with plastic screws. But later this was considered nonviable due to the complexity of its usage in emergency environments, locking different parts was considered. The design will be modified accordingly in the coming days.

Accomplishments that I'm proud of

Before beginning the PROPE Visor project, we were able to 3D print about 100 head bands for the visors for the regional hospitals and healthcare centers. We hope this innovation will also help the efforts and keep the healthcare professionals free from the virus.

What I learned

Any piece of technology that is commercially available can be used to produce the desired specific functionality of an equipment. Particularly, during the crisis when medical equipment are in shortage and the components they are built with are in high demand worldwide, alternative components from other relevant industries are of immense help.

What's next for PROPE

Improving the design so that the different parts of the assembly are connected with locking mechanism rather than with the help of plastic screws. Designing a compartment and a waist fixture for the batteries. Characterizing the level of cleanliness with a particle counter to validate the ISO cleanroom standards. Adding a safety feature to indicate the low battery level with a flashing light in front of the face.
We would like to 3D print and assemble the first batch of PROPE Visors and bring them to hospital and healthcare workers to use. The local government may help for mass production. We would like the help of EUvsVirus team to assess the simplicity and effectiveness in adapting the concept in European and global scale.

Built With

• 3d-printing
• cad-design