I sleep with 2 liters of oxygen at night. The machine is big, heavy and noisy. My caregiver says there is no other option for when I travel except to take it with me or order one to use on the other end. The thing puts out 70 decibels of noise. Is there really no quiet, light weight device that will do the job? I’ve seen and get ads for different portable devices- would any of them do the job