My wife has to use one of those machines. The medical supply company that we rent it from says that it has an internal record-keeping device that records the duration of time for each 24 hour day that it's used. If it isn't used enough to qualify for Medicare reimbursement the feds won't pay for it. IIRC the minimum time is 4 hours, but I'm not 100% sure of that. Which make good sense IMHO, Medicare and Medicaid shouldn't be paying for anything that isn't necessary.
Quote” What should a CMV driver do after learning that they have sleep apnea?
Each state sets its own medical standards for driving a commercial motor vehicle in intrastate commerce. Many States have adopted the medical regulations found under Section 391.41(b)(5) of the FMCSRs and have determined that sleep apnea is a disqualifying condition. Each State has the jurisdictional authority to suspend a CDL if a person has sleep apnea. Medical examiners and CMV drivers should check with their Department of Motor Vehicles for more information about medical standards in their State.
What level of sleep apnea (mild, moderate, severe) disqualifies a CMV driver?
The disqualifying level of sleep apnea is moderate to severe, which interferes with safe driving. The medical examiner must qualify and determine a driver’s medical fitness for duty.
What are the obligations of a motor carrier concerning an employee with sleep apnea?
A motor carrier may not require or permit a driver to operate a CMV if the driver has a condition, including sleep apnea, that would affect his or her ability to safely operate the vehicle.
“
http://www.fmcsa.dot.gov/safety-security/sleep-apnea/industry/commercial-drivers.aspx