nSPHERE pressurized helmet is a personal protective equipment to guard user from harmful airborne contaminated droplets. Pressure difference between inside the helmet and surrounding is exploited to create two protection categories. Positive pressure (> 5 Pa) is exploited to shield the user from dust/particles outside the helmet, match for medical staffs who are in contact with patient. Conversely, negative pressure (< -4 Pa) is used to contain contaminated droplets within the helmet, suitable for patients who have potential risk of spreading pathogens. Safety issues have been addressed by integrating pressure sensors for real-time pressure difference monitoring with LED indicating working status of the helmet. The contaminated air is purified by a filtration unit (efficiency of 99.97％ ＠ 0.3 µm DOP, protection factor higher than N95 mask).