How Does an Electric Wheelchair WorkOctober 14, 2021
You might have a loved one who uses an electric wheelchair or you might be looking to upgrade from a manual wheelchair to a power wheelchair for yourself for greater ease and comfort. Electric wheelchairs enable a greater sense of autonomy for the user and whatever the case may be, it is interesting to know how it works.
Electric wheelchairs work by using batteries to power motors within the base of the chair, enabling the user to control their wheelchair with a basic videogame-like joystick that is within reach on the armrest. Other electric wheelchairs can be controlled by voluntary physical movement.
The technology of electric wheelchairs certainly has come a long way. While basic electric wheelchairs are typically controlled by joystick style controllers, electric wheelchairs have been made even more accessible by offering advanced options to control the device through voluntary physical movements involving the chin, tongue, breath actuation, and lower body control. Read on to learn more about how this happens.
The Mechanics of an Electric Wheelchair
Electric wheelchairs use wet or dry cell sealed lead acid batteries that can be easily recharged in a standard power outlet when not in use. One thing to keep in mind is that the size of the battery can make a difference to the weight and overall size of the power wheelchair. While some might choose a chair with a Group 22NF battery which is compact and suited to indoor, level surface use, others may select a power chair with a Group 24NF battery that is slightly larger but better accommodates outdoor mobility with different terrains. Replacement batteries can easily be found to purchase online.
The batteries are what generate electricity for the motor, also located in the base of the power chair. These motors can be found in either a two-pole or four-pole option both with their own set of advantages and downsides:
|Two- Pole Motor||Four- Pole Motor|
|Draws less power from the battery||Draws more power from the battery|
|Better suited for slow smooth operation||Higher torque leads to rougher operation|
|Better suited to cramped, indoor conditions, and level terrain||Better suited to uneven outdoor terrain|
|The wheelchair becomes inoperable if one brush on either pole fails||The wheelchair will still operate if one brush on one pole fails|
Understanding these mechanical differences can help you make an informed decision on which type of electric wheelchair is best suited to your lifestyle and mobility. These factors can influence the size of the power chair along with how to use it. Another way electric wheelchairs vary in function is through the method of control.
Types of Controller Interfaces Used for Electric Wheelchairs
There are a plethora of reasons you may need a control option other than the conventional joystick, such as your body’s range of movement and the type of space you wish to use your power wheelchair in. Having these options increases accessibility and customizability.
Typically found at the end of the armrest, the conventional joystick functions much like a videogame controller and is intuitive to use. Simply move the controller in the direction you wish to travel and the further you push the joystick, the faster it will move. Releasing the joystick immediately stops the movement of the wheelchair. This controller may sometimes have an on/off switch along with power indicator lights right on the joystick panel. The position of the joystick controller can also be customized for increased usability.
Similar to the conventional joystick, with direction and speed being achieved the same way, a chin control is a smaller version of the joystick operated by the chin. It is mounted just forward of the chin and the knob can be customized for greater comfort of use.
The controlling mechanism for this option is mounted behind the head and stimulated by the directional movement of the user’s head (to turn left, you would move your head to the left). There is usually a separate and accessible switch that enables head-controlled electric wheelchairs to be put in reverse when pressed and then pressed again to resume forward motion.
The tongue is an intuitive way the body can navigate mobility in any posture. A device is fitted to the roof of the mouth that acts as a sensor for the movement of the tongue to predetermined positions in the mouth. For example, you might touch the left side of the roof of your mouth with the tip of your tongue to turn left.
Wafer Board Control
If an electric wheelchair user prefers to control their device by hand but requires something with less sensitivity than a joystick, a wafer board provides this option. A wafer board control is usually located on the lap or wheelchair tray for easy visibility by the user with switches to move forward, backward, and side-to-side.
Sip and Puff Control
For those with extremely limited mobility, this option may be ideal. With this control, the wheelchair user inhales or exhales into a tube at varying degrees of strength to equate to a motion. For example, a forceful exhalation (puff) might propel the power chair forward while a gentle puff stops it. This control option may require some time to master but is still a technological feat.
Scanner Drive Control
This type of control has a switchboard with a customizable location for ease of reach with four directional lights that flash in a clockwise pattern. When the light facing the direction of desired travel is lit, then you would flip the switch to move in that direction. For example, when the light on the right is lit, you can press the switch to go right.
There are many factors taken into account that impact how an electric wheelchair works. This technology has come a long way since its invention and understanding some of the mechanical and functional differences can play an important part in deciding which option is best for you or a loved one.
By Trevor Fenner
About the author:
Trevor Fenner is the founder and owner of Mobility Paradise, a one-stop-shop for all kinds of mobility equipment. Years ago, Trevor’s grandma had an accident that made her dependent on a wheelchair; this forced Trevor and his family to put her into an elderly care facility. Since then, Trevor would visit her to take a walk around the neighborhood. Mobility Paradise was born out of Trevor’s frustration finding an online store that offers a wide selection of mobility equipment paired with suitable resource materials. What started as a business focusing on electric bikes grew to include all kinds of mobility products. You can shop for the most reliable mobility products at Mobility Paradise.