Sunrise Medical’s newest power-assist system sits under the manual wheelchair’s seat to preserve the chair’s original footprint and turning radius while retaining great maneuverability.

The manufacturer officially launched the Empulse R90 in a Sept. 9 news announcement.

“The patent-pending V-Lock is a tapered latch that securely docks the R90 to the receiver on the chair,” the announcement said. “Combined with the ergonomic, easy-grasp handle, upright orientation, and rolling tire, the R90 can be attached easily and securely. And when the R90 is not needed, you can raise the wheel for zero rolling resistance with the patent-pending wheel-up function. While the R90 is easy to remove entirely, it’s even easier to raise the wheel with the push of a button and keep it on your chair all day.”

On rigid-framed chairs, the receiver bracket mounts to the camber tube and can remain there even when the R90 is off the chair. The assembly for a folding chair includes “a sturdy crossbar that is spring-loaded for quick installation and removal,” Sunrise Medical added.

The Empulse R90 automatically reduces speed when the rider is going around sharp corners, and the system also can discern slopes or obstacles and provide more or less power to maintain the rider’s speed.

And because the R90’s wheel “closely aligns” with the manual wheelchair’s rear wheels, the power-assist’s wheel and the chair’s rear wheels go over obstacles at the same time.

The R90’s wireless control box links to the power-assist system via Bluetooth, and push-button propulsion enables riders to start and control their speeds easily. The control box can be mounted anywhere on the chair’s tube frame. Use the Sunrise Intelligence App to select the best performance profile based on indoor or outdoor environments. Preset drive profiles were created for “specific environments for speed, torque and slope thresholds,” Sunrise Medical said.

The R90’s standard battery — airline compliant and with range up to 9.8 miles — can be swapped for an extended-range battery (up to 19.5 miles).

“All these features make the R90 easy to use, but the real highlight is its versatility,” said Bernd Krebs, Sunrise Medical’s Chief Technical Officer. “We did extensive field testing, and our riders enjoyed the great maneuverability, compactness and range, as well as the wheel-up function.”

The Empulse R90 package includes the power-assist device; a standard, removable battery; a control box with short and tall mounting plates; a charger; a receiver assembly; and a travel bag. Options include an extended-range battery, additional standard batteries, and a docking charger that accommodates standard and extended-range batteries.

The power assist has a rider weight capacity of 275 lbs. and a top speed of 5.5 mph. The R90 weighs 14.5 lbs. with a standard battery and 15.6 lbs. with an extended-range battery.