Motorized wheelchair

A motorized wheelchair, powerchair, electric wheelchair or electric-powered wheelchair (EPW) is a wheelchair that is propelled by means of an electric motor rather than manual power. Motorized wheelchairs are useful for those unable to propel a manual wheelchair or who may need to use a wheelchair for distances or over terrain which would be fatiguing in a manual wheelchair. They may also be used not just by people with 'traditional' mobility impairments, but also by people with cardiovascular and fatigue-based conditions.

The electric-powered wheelchair was invented by George Klein who worked for the National Research Council of Canada, to assist injured veterans after World War II.

Powerchair design may be categorized by drive system/chassis, battery, controller, seat, and use.

Powerchairs are generally four-wheeled or six-wheeled and non-folding, however some folding designs exist and other designs may have some ability to partially dismantle for transit.

Four general styles of powerchair drive systems exist: front, centre or rear wheel drive and all-wheel drive. Powered wheels are typically somewhat larger than the trailing/castoring wheels, while castoring wheels are typically larger than the castors on a manual chair. Centre wheel drive powerchairs have castors at both front and rear for a six-wheel layout.

Powerchair chassis may also mount a kerb-climber, a powered device to lift the front wheels over a kerb of 10 cm or less.

Some manual wheelchairs may also be fitted with an auxiliary electric power system. This can take one of three forms: integrated with the hub of hand-propelled wheels, so that any force on the pushrims is magnified by the drive system, or mounted under the wheelchair and controlled as for a powerchair, but with the motive force either transmitted to the main wheels via a friction drive system, or delivered directly through an auxiliary drive wheel.

Some experimental all-terrain powerchair designs have been produced with tracks rather than wheels, but these are not in common use.

Other experimental designs have incorporated stair-climbing abilities and Dean Kamen's iBOT design featured both stair climbing and the ability to 'stand' on its upended chassis via the use of advanced gyroscopic sensors. The iBOT was at one time a production model, but is no longer marketed.

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Wikipedia