An electric wheelchair is also referred to as power chair, motorized wheelchair, or electric-powered wheelchair (EPW). It is a wheelchair that is propelled via an electric motor rather than manual power. Electric wheelchairs are useful for those with inability 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 are also used by people with cardiovascular and fatigue-based conditions and not just by individuals with 'traditional' mobility impairments.
China, Canada and Taiwan are the largest manufacturers of electric wheelchairs. In 2004, Canada exported electric wheelchairs worth $1.9 billion to the United States. However, there was around 114.1% increase in the export of electric wheelchairs from Canada to the United States up to the tune of $4.1 billion.
Electric wheelchairs are commonly four- 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 Electric chair 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 electric wheelchairs have castors at both front and rear for a six-wheel layout.
The modern electric wheelchairs are structurally similar; however the various functions available make each unit unique. There are four basic parts of every electric wheelchair; these are the electric motor, the battery, the drive and the controller. The lightweight electric wheelchair uses a 2-pole motor, while the heavy duty electric wheelchair uses a 4-pole motor which expectedly has more carrying power and also enables additional important options.
The electric wheelchair as mentioned earlier, uses sealed lead acid batteries that can either be wet or dry batteries with an output of 4 to 5 amps. These batteries can be recharged using a standard electrical outlet when the chair is not in use. Notably, the electric wheelchair is steered using a joystick or handle. However, for severely disabled individuals, there are other control options including head to chin controller, motion sensitive tube or even an eye-to-computer screen control. The computer interface uses the battery power to operate and every user is warned or advised by the computer of low battery and signals the need for recharging. In addition to the primary speed and steering uses of the controller, it likewise manages the tilt, the lifting and reclining functions of the electric wheelchair.
However, since the advancement in technology, there have been other programmings done to the electric wheel chairs making it controllable even without the joystick but rather by using any voluntary movement. For instance, some electric wheelchairs can be controlled by using breath actuation, tongue movement, head movement or even lower extremity control.
Basically, according to the different parts, the electric wheelchair starts using the switch control powered by the lead acid batteries and with the aid of the motor, different movement options are performed.