Monitoring system including mask removal and oxygen desaturation period detection

A method of approximating a position of an oxygen mask during a procedure, the method comprising:

• detecting a presence of the oxygen mask based on a signal from a sensor or through an observation through an optical imaging device;
• determining, via the sensor or the optical imaging device, whether the oxygen mask is close to or on a patient for supplying oxygen to the patient;
• detecting, via the sensor or the optical imaging device, a removal of the oxygen mask from the patient to stop supplying oxygen to the patient;
• initiating, via one or more processors, a desaturation timer in response to the sensor or the optical imaging device detecting the removal of the oxygen mask from the patient;
• operating, via the one or more processors, an image display device to display a parameter for the oxygen desaturation timer.