Even today many patients who need oxygen constantly supplied must wheel around tanks that weigh 35 pounds.
But life is getting easier for sufferers.
"As technology advances, it's easier for our customers to become more ambulatory or mobile," said Collamore, a therapist with BritKare Home Medical in Lubbock, Texas.
Units are smaller and lighter - some less than 5 pounds.
Technology also conserves oxygen by only expelling a puff of air when a patient inhales.
The difference reduces the amount of oxygen patients use and the number of refills they receive.
Some forms of oxygen tanks are now approved for air travel.
Jennifer Bouressa, BritKare marketing director, said airlines once charged up to $200 a flight to use their oxygen.
The most recent customer advantage has been the advent of home-filled tanks.
Equipment pumps outside air through a filter that removes contaminants, such as nitrogen and carbon dioxide, and leaves pure oxygen for the patient's tank.
Patients can fill a tank that lasts about six hours in just two hours.
"This is just another way for us to cater to the oxygen concentration," BritKare's Chris Sledge said.
Baldridge said a delivery of oxygen lasts about a week on average.
With a home-filled tank, patients can go longer between oxygen deliveries, reducing their dependence on oxygen-supply companies.
"With gas prices, we're trying to streamline our services," Sledge said.
Some units do away with oxygen tanks all together.
They use technology similar to the home-filled units to supply a steady stream of oxygen for the patient, "so they're not tied down to a large tank or hose," Collamore said.
BritKare's portable unit weighs 4.4 pounds.
But not every oxygen supplier has such equipment.
Oxygen-supply companies are forced to adjust to lighter customer demand, and workers make fewer deliveries.