There is a world wide pandemic of crisis dimensions. There is a shortage of personal protective equipment (PPE) putting medical personal and first responders at risk.
The extremely invasive nature of this specific virus makes it mandatory to protect all mucous membranes of the head including the mouth, nose and eyes. Covering the ears may not be essential but might be helpful.
I am suggesting a simple solution for personal protective equipment to address this emergency condition. It is based on my career as a dentist, an undergraduate program in microbiology and a work/ study job while in college.
I worked in a food micro laboratory under Dr Banwart at Ohio State. I was very successful at growing tissue cultures on which we were growing polio virus. To prevent contamination from the outside air there was a positive air flow unit so no foreign bacteria, viruses, spores, mold could enter the chamber. The airflow would prevent this completely. There was also a negative air flow vent to prevent escape. of materials. This would be a more difficult question and is not necessary for Personal Protective Equipment designed to protect health workers.
As a dentist we frequently vacuum form trays to make mouth-guards and bleaching trays. Combining these materials could give us custom made PPEs to protect those at highest risk. 3D printers are being utilized to create face masks but that is a slow process. and time is of the essence.
The thin plastic trays found inside food and other packages is ideal for being molded via a thermoplastic approach. These materials are extremely light weight and transparent and will not allow penetration of viral particles. The surface is easily cleaned but they are still disposable.
The chief problem with a helmet would be fogging and prevention of virus laden particles being sucked into the mask.
The following proposal is offered free to anyone and everyone who is interested in helping our amazing health workers, paramedics, doctors, physical therapists, police, firemen and all hospital workers.
It is a simple proposal a Vacuum formed or pressed die form plastic is made out of a single sheet of thermoplastic material. It is designed to fit over the head with space to cover a several inches past the chin and covering the neck but relieved for the shoulders. It will be a very lightweight plastic that can be stabilized with velcro tapes or double sided tapes to clothes but still be easily removable. A array of micro-motors such as those used to cool computers can be attaches with simple input filters to create a positive air flow which will prevent any virus particles from entering the mask. Small packets of silica sand or similar absorbent materials can be attached for moisture removal.
Packaging engineers are the experts at creating custom molded plastics for almost everything. The mask can be made large enough so as not to be claustrophobic. The mask could be made in two pieces that are fit together and secured with adhesive when donning for a more custom fit. This could also allow it to be worn with passive pressure on the shoulders. This could be done with or without adhesion to clothes with velcro strips or simple double sided tape. If there were any gaps positive air pressure would prevent them from being problematic and they may even improve comfort.
Two piece helmets could be stamped out incredibly fast. This would allow sizing so that several sizes could be made. They could snap together easily.
The airflow needs to be strong enough to overcome the risk of inspiration creating a negative air pressure that could suck air into the mask. We also need to prevent fogging but the positive flow of air will remove humidity along with silica sand packets. Without positive air pressure it could still be utilized with any existing masks.
There will be no way to eat or drink liquids in a normal fashion but water bottles with straws extending to the mouth be used. Ideally the straws can be attached to the anterior of the shells so they can easily be pushed into mouth by pressure on the outside.
These are designed to protect the health worker and not the patients who are already infected but they will still eliminate the bulk of risk of the health worker spreading virus or bacteria to patients.
It is essential that there be filters at the intake. Ideally minimal visual distortion will be caused by the helmet. This would entail some control of shape of front panel similar to face shields. These could be made with 3D printers but the process would be slow compared to preformed thermoplastic material that are readily available.
The fans need to be very small, quiet and available in large numbers very quickly. Low power requirements to be run off battery or mini photo-voltaic cells. Ideally they should be easily moved when helmets are changed. A filter is needed at the air intakes.
If micromotors were not available larger battery powered fans could be used with batteries placed in pockets of the workers.
These can be made so quickly that once the urgent needs of health care workers are met they could be quickly produced for the public for trips to grocery stores etc.
For the record this was inspired by a small piece of packaging made by Cool Pak (cool-pak.com). I looked at the bottom and it is made 100% from recycled bottles, weighs practically nothing, is completely clear and is recyclable (1 RPE).
Regent, Master & Fellow, International College of CranioMandibular Orthopedics
Board Eligible, American Academy of CranioFacial Pain
Member, American Equilibration Society
Member, Academy of Applied Myofunctional Sciences