Auto-titrating Oxygen and Chronic Obstructive Pulmonary Disease (ASI1)

Long term oxygen therapy (LTOT) increases the life span of patients with chronic obstructive pulmonary disease who have low oxygen levels. However, even when on oxygen therapy at home, from time to time patients still have low oxygen levels especially when walking which can be harmful.

The investigators have designed a new system of delivering oxygen to overcome the above problem. The system measures the oxygen saturations of a patient and subsequently adjust the flow of oxygen to meet a pre-set oxygen saturation target.

Hypothesis: the investigators intelligent oxygen therapy system is better at reducing low levels of oxygen during a 6 minute walk than usual ambulatory oxygen for patients with chronic obstructive pulmonary disease on long term oxygen therapy.