TAMPA, Fla. – The effects the increasingly prevalent sleep disorder obstructive sleep apnea (OSA) have on a professional driver have been well documented. However, there’s growing concern about the impact in-cab use of continuous positive airway pressure (CPAP) devices – the machines used to treat the condition – are having on the power supply of a vehicle and the safety of drivers.

A group of experts converged on the Technology & Maintenance Council meetings to discuss power management strategies for in-cab sleep apnea devices. Among the panelists was Tim DiSalvi, director of loss prevention for Schneider National, which is among the most proactive fleets in screening and treating drivers with the sleep disorder. DiSalvi said the fleet is having trouble finding a power solution for CPAP devices, which draw about four to six amps per hour, resulting in a total requirement of 40-60 amps over a 10-hour rest period.

“The immediate solution was to idle the truck,” DiSalvi said. “That is one way to go, but obviously there are some challenges with idling restrictions and it just doesn’t make sense from a financial perspective to have to idle the truck when it’s not necessary.”

Schneider doesn’t equip company trucks with auxiliary power units (APUs), as the fleet has yet to make a compelling business case for the equipment, and the truck’s primary batteries are in many cases unable to power the CPAP machine for an entire 10-hour rest cycle without compromising startability the next morning or triggering a low voltage disconnect.

“Early on, the batteries were draining down and causing the CPAP device to shut down in the middle of the driver’s rest period,” DiSalvi noted.

Power inverters are one potential fix, and another option is to power the CPAP device off a separate battery, ensuring the truck is able to start in the morning.

Paul Menig, CEO of Tech-I-M, said CPAP devices are adding strain to an electrical system that’s already pretty much tapped out.

“Today’s engines require more electrical energy to be able to start, especially in cold conditions,” he explained. “Batteries are regularly drained by the comfort items in the cab. Truck OEMs are already challenged without taking on additional loads required by heated, humidified medical equipment.”

Bruce Purkey of Purkeys Fleet Electric agreed, adding: “Over the last several years, we’ve had new anti-idling policies, rising fuel costs and increased electrical load demand. The result has been less available energy to start the vehicle every morning when we get ready to operate this vehicle. Fleet customers are now saying we have medical devices that can pull six to 10 amps and it has to run all night. Is this the straw that broke the camel’s back?”

Nobody on the panel denied the importance of supplying power to CPAP machines; in fact it was noted a driver’s continued use of CPAP therapy is crucial to their safety. However, powering the devices remains an elusive challenge. Purkey suggested the CPAP machine should have its own power source so it doesn’t risk draining the trucks’ batteries or lose power overnight. He also said it should plug into a standard power outlet so it’s easy for drivers to use.

Schneider’s DiSalvi issued a challenge to CPAP manufacturers: “Be mindful of the limited power that’s available and ensure the CPAP devices are efficient in their power usage.”

Menig said he’s concerned suppliers will begin building multi-purpose CPAP machines with everything from alarm clock capabilities to iPod adaptors built in, increasing their power requirements.

Randy Thinnes, representing CPAP manufacturer Res-Med, said he’s cognizant of the trucking industry’s concerns, and announced the development of a new device that runs entirely off 12- or 24-volt DC power sources.

“A 12- or 24-volt DC converter replaces the AC power supply with no need for an additional inverter,” he said.
He predicted the new offering will be a huge development for in-cab CPAP usage.

“A fully DC device is huge,” he said. “It’s going to improve the efficiency, being able to utilize a single DC power source.”
Not only are truck fleets struggling to find power for CPAP devices, they’re equally frustrated with the absence of a safe, secure place to position the device while in use.

“These devices were originally built for use in the home,” admitted Res-Med’s Thinnes. “There was never any concern for mobile applications.”

DiSalvi noted “Our drivers will place it on top of storage bins, which is not ideal, especially in team configurations.”

The machine has the potential to fall and break, and water can slosh from the humidifier reservoir into the electronics if the machine falls from its perch. Some team drivers have also received an unwelcomed shot of water up the nose from excessive movement of the vehicle, something akin to waterboarding and not exactly conducive to restful sleep. Storing the unit on the floor presents challenges as well, such as tripping hazards.

“We have to at least find a way to store this,” said Menig. “We don’t want six feet of tubing and six feet of wires going around the floor of the cab as the driver moves in and out of the sleeper.”

Some do-it-yourselfers have come up with their own installations, Menig said, but when bolting inverters or shelving units into an existing cabinet, he warned drivers or fleets to check with the OEM first to see if the cabinet walls can support the additional weight.

“In our view, we would advocate for a particular space designed for the CPAP machine that would be secure, doesn’t include bungee cords, a secure location close to power and even an additional separate battery for the CPAP unit in the sleeper berth so it’s able to go from one truck to another without having to move an inverter,” DiSalvi implored.