Deforestation and climate change are drastically transforming the global ecosystem by changing the interface between humans and animals: the anthropogenic pressure due to the compromise of  habitat  natural and the consumption of  bushmeat  (forest meat) exponentially amplify the conditions of contact between humans and wildlife. Several researches indicate, for example, that bats are  reservoir  of viruses responsible for dangerous infections (Ebola, Nipah, Hendra e  different Coronaviruses).

 

 

The phenomenon of the species jump of pathogens,  spillover, once rather sporadic (Smallpox, Diphtheria, Poliomyelitis, Measles and more recently AIDS) has now become very frequent: over the last twenty years, before the current emergency, new diseases of animal origin, transmissible mostly through the airways, such as SARS, MERS, Influenza A / H1N1.   The spread of the virus  SARSCov2, responsible for the named pathology  COVID-19,  due to the vastness and speed of propagation it had a devastating impact on a global level. By changing working and personal relationships, social life more generally, with a particularly high social and emotional cost, has highlighted the present and future limits of our society with respect to global pandemic risks.

The greater diffusion of technologies, in developed countries, has made it possible to safeguard working relationships and social relations at a distance, implementing a transition that was now necessary in some fields but, in many other cases, such as medicine, education and transport. urban areas, industrial manufacturing and professional activities, has not made it possible to avoid major social and economic problems.   In the most backward countries, as well as in the groups less accustomed to the use of IT tools, as a consequence, the so-called  digital divide  and even more critical situations arose.

The world, enriched by parallel virtual reality, has become impoverished in human terms, with the worsening of the costs of long-distance relationships. The safeguarding of the primary interest of collective health has been opposed to the general economic interest, requiring in many cases the contraction of universally recognized personal rights.

In terms of the currently existing protection and isolation devices from pandemic transmission, the emergency has highlighted significant limits. The difficulty in procuring the devices, the reduced efficacy and safety, the lack of ergonomics and the limited environmental sustainability emerged immediately (since these are mostly disposable devices).

 

In terms of containment and isolation, the lack of infrastructures to isolate potentially infected subjects has emerged, if not by resorting to expensive bio-containment departments, the differentiation of paths,  triage, to the drastic reduction of social and human relationships especially in any situation in which subjects with specific frailties (elderly, immunosuppressed, etc.) were involved.  

From these considerations, the need arose to develop a technological tool capable of providing greater protection for health and non-medical personnel, allowing in absolute safety and health, the resumption and / or continuation of working life, relationships, education, transport mass; at the same time, the need arose to develop a system capable of allowing the isolation of potentially infected subjects, without resorting to the use of expensive infrastructures, in terms of resources, spaces and times. The product produced is the result of a scientific and research activity conducted in UNIPA.

The spread of diseases by airways occurs when a healthy individual comes into contact with a quantity of particles of the pathogen (in the case of viruses, the so-called viral load). It is known that in diseases transmissible by air, the biological agent emitted into the environment by the infected subject can enter the healthy individual indirectly, by contact from fomites (i.e. through contact with surfaces exposed to the pathogen and subsequently with the face or mucous membranes of the healthy subject) or directly, by contact with the eyes and inhalation by the healthy subject of particles from the infected individual. In this case the propagation distance is variable in relation to the pathology.   

 

Some pathogens can only spread through  droplets  - drops not less than 100 in size  m  made up of secretions from the airways such as mucus or saliva released into the surrounding environment with sneezing or coughing - which quickly fall back to the floor. Others even persist on aerosols - droplets smaller than 100 in size  m  - thanks also to   conditions of humidity and temperature, locally present in the exhalations, and can reach much greater distances or remain in suspension. The use of filters with filtering capacity calibrated from time to time according to the need, allows to prevent the passage of more or less large particles (eg HEPA, ULPA or activated carbon filters with filtering capacity lower than  m).

 

Taking into account, then, that the entry and exit routes of these infections are mostly localized in the head area (eyes, nose, mouth), the use of an envelope that allows their integral containment, increases the level of safety both in case of protection than in case of isolation.  

 

It is also known and widely used in the construction of infrastructures with particular protection requirements, the principle according to which the maintenance of a slight overpressure between the inside of the premises and the outside, prevents the entry of unwanted particles from the outside (e.g. complex operators , microelectronics industries,  NBC bunker). Conversely, by maintaining a slight depressurization in the internal rooms it is possible to avoid the accidental escape of dangerous substances such as pathogens (research laboratories with bio-containment, highly infectious disease departments). This principle is applied in the device conceived by means of forced ventilation which allows to maintain a  D.  preset pressure (for example 10 mBar).