The Indian Institute of Technology Kanpur (IIT-K) and Sanjay Gandhi Post Graduate Institute of Medical Sciences (SGPGIMS), in a joint project, have developed a working prototype of a Positive Pressure Respirator System (PPRS) to address the problem of acute global scarcity of N-95 respirator masks which are a critical component of Personal Protection Equipment (PPE) kits.

The team behind the project include Professor Nachiketa Tiwari of IIT-Kanpur and Professor Devendra Gupta, in-charge, COVID-19 ICU at SGPGIMS. Prof Tiwari said that the PPRS is a much safer alternative to the N-95 respirator since the existing N-95 respirator does not protect the user if there is an imperfect seal between the mask and the face, as there is negative pressure inside the mask.

"In contrast, the PPRS provides uncontaminated air by using positive pressure. Thus, contaminated air from the room cannot enter the PPRS even in presence of any leakage," Prof Tiwari explained. He said that as compared to the PPRS, N-95 respirator is only 95 per cent efficient, thus posing risk of infection to health professionals working in isolation wards with large number of Corona infected patients for longer durations. The PPRS eliminates this risk as well.

The PPRS is essentially made up of a comfortable and leak-proof transparent enclosure for mouth and nose, which receives positive pressure air from a portable, light, and wearable air-bottle. It also has a trolley-mounted oxygen cylinder. The device can deliver uncontaminated air for over six hours. It uses locally produced reliable one-way valves to avoid the inflow of contaminated air.

The new PPRS incorporates multiple design features to protect the user from contamination and has a free size design. Prof Tiwari said that the PPRS devices can be produced in very large numbers in a very short time frame across the country. The design team has also developed a product-process video, which can be viewed to manufacture the device locally.