Inspiratory time is typically measured in seconds or fractions of a second. In mechanical ventilation, ti can be adjusted using the ventilator settings. The respiratory rate (RR) and the inspiratory-to-expiratory (I:E) ratio are commonly used to set ti. For example, if the RR is 30 breaths per minute and the I:E ratio is 1:2, the inspiratory time would be 1 second.