In my PhD project, I explore how air moves in and around operating rooms.
Why does this matter for patient safety? By studying airflow and ventilation in a full‑scale operating room lab at NTNU, we can uncover insights that may help hospitals reduce infection risks and create better conditions for both patients and surgical staff.
The Operating Room Lab at NTNU is a full‑scale, fully instrumented mock operating theatre where we explore how the surgical environment can become safer, more energy‑efficient, and more comfortable for both patients and staff. The lab gives us a rare opportunity to test new ideas in conditions that closely resemble real clinical scenarios.
Our research focuses on three key challenges:
- Reducing airborne infection risk
- Maintaining thermal comfort for patients and surgical staff
- Improving energy efficiency in operating rooms
My own work lies at the intersection of infection control and thermal sensation. Surgical‑site infections can be partly caused by airborne particles. Since airborne particles travel with the air, understanding the airflow behaviour around the surgical site is crucial. Even small disturbances can influence whether particles are carried towards or away from an open wound.

In the operating room, airflow is shaped by many factors such as:
- The type of ventilation system
- Surgical lights, equipment, instrument tables, and other physical obstructions
- Human movement, such as staff leaning over the patient or stepping back during a procedure
To study these complex interactions, we need to be able to see the air. Traditional smoke visualisation can give a rough impression of airflow, but it cannot reliably capture the direction and magnitude of air movement.
Tracking particles in the air

That’s why we use Particle Image Velocimetry (PIV), an optical method that employs a thin sheet of laser light and high‑speed cameras to track the motion of tiny tracer particles in the air. By taking two images only microseconds apart, we can measure how far each particle has moved and in which direction. This lets us reconstruct airflow patterns with remarkable detail, including their transient, moment‑by‑moment changes.
These insights help us understand how ventilation systems behave under real operating‑room conditions, and how they might be optimised to reduce infection risk without compromising comfort or energy use.
If you’re interested in saving lives while working with lasers, airflow visualisation, and full‑scale surgical environments: This is definitely the right lab to be in.
Introduction to the Operation Room lab (video)
About Kunal Bairwa

Kunal Bairwa is a PhD Candidate at NTNU – Department of Energy and Process Engineering from 2024. His PhD project is affiliated with the project Human-Centric Indoor Climate for Healthcare Facilities (HumanIC), funded by the European Union’s Horizon Europe research and innovation program under the Marie Sklodowska-Curie. His supervisor is Prof. Guangyu Cao, and his co-supervisor is Prof. Hans Martin Mathisen.