An oxygen delivery device includes an oxygen delivery module configured to deliver a pulse including greater than 100 mL of concentrated oxygen, and a controller configured to control the oxygen delivery module to cause the oxygen delivery module to deliver the pulse including greater than the 100 mL of the concentrated oxygen within approximately first 60% of a patients inspiratory period. A device includes an oxygen delivery module, a piezoelectric valve coupled to an output of the oxygen delivery module to receive the concentrated oxygen, a driver to electrically actuate the piezoelectric valve, and a controller to control the driver to cause controllable actuation of the piezoelectric valve by the driver to cause controllable opening of the valve to enable oxygen flow to be directed for inhalation by a patient via the piezoelectric valve.