Anaesthesia physics involves understanding the principles and functioning of monitoring devices used during anaesthesia to ensure patient safety and optimal care, including respiratory monitoring devices (such as spirometers, capnographs, and pulse oximeters) to assess breathing and gas exchange, cardiac monitoring devices (like ECG, blood pressure monitors, and cardiac output monitors) to track heart function and circulation, neuro monitoring (including EEG and BIS monitors) to evaluate brain activity and depth of anaesthesia, and neuromuscular monitoring (such as nerve stimulators and train-of-four devices) to measure muscle relaxation and recovery during surgery.