Operating rooms use laminar flow systems to create a continuous shield of sterile air over the patient.

Laminar Air Flow (LAF) systems were first introduced to surgical environments in the 1960s by Sir John Charnley, a British orthopedic surgeon. He realized that traditional ventilation systems created turbulence, which kept particles suspended in the air. By implementing a unidirectional flow system, Charnley reduced infection rates in hip replacements from 9% to less than 1%.Modern systems utilize High-Efficiency Particulate Air (HEPA) filters that remove 99.97% of particles as small as 0.3 micrometers. The air moves at a velocity of approximately 0.3 to 0.5 meters per second. This speed is sufficient to overcome the thermal plumes generated by the heat of the surgical team and equipment, ensuring that contaminants do not settle on the open wound.Studies published in the Journal of Hospital Infection highlight that humans shed about 10,000 skin scales per minute while walking. Many of these scales carry bacteria like Staphylococcus aureus. Laminar flow creates a 'piston effect' that captures these particles and drives them toward floor-level exhaust vents before they can reach the patient.While highly effective for orthopedic and cardiac surgeries, the World Health Organization (WHO) continues to study its cost-effectiveness compared to standard ventilation. However, many specialized surgical centers consider it the gold standard for maintaining an ultra-clean environment. The technology remains a cornerstone of modern bio-clean room engineering and infection control protocols.