NIST research assistants demonstrate how the prototype robotic HLPR chair facilitates leg exercise.

NIST research assistants demonstrate how the prototype robotic HLPR chair facilitates leg exercise.


The HLPR chair could lift persons to reach high shelves.

The HLPR chair could lift persons to reach high shelves.


The robotic system could let users move to and from beds, chairs, and toilets without assistance, significantly reducing caregiver and patient injuries.

The HLPR chair draws on mobile robotic technology developed at NIST for defense and manufacturing. It is built on an off-the-shelf forklift with a U-frame base on wheellike casters and a rectangular vertical frame. The frame is small enough to pass through typical residential bathroom doors. The user maneuvers the chair with a joystick and other simple controls.

The HLPR chair's drive, steering motors, batteries, and control electronics are positioned to keep its center of gravity within the wheelbase when carrying a patient. The lifts can move a 300-lb person and safely lower them. The chair frame can even remain in position to continue protecting the patient from a possible fall.

The prototype chair would also let stroke victims and others keep their legs active without supporting their entire body weight. The retractable seat and foot rests, padded torso lifts for under the arms, and open frame at the bottom of the chair facilitate leg exercises. The patient, once lifted and supported, can walk as the HLPR Chair moves forward. The maximum speed is 27 ips (0.7 m/sec). NIST engineers expect the HLPR will autonomously dock with toilets, operate by voice activation so patients can call it from another location, and feature dial-in leg loading to limit forces during rehabilitation.