Alternative ways to control a power wheelchair

Power wheelchairs can be a great way for people with limited mobility to get around.  The standard way to control a power wheelchair is via a joystick typically mounted on either side of the wheelchair.

However, if you have a limited range of motion or strength, then using the standard joystick may be difficult. There are a growing number of alternative options that are becoming available.  These include light touch mini joysticks, switches, touchpads and sip and puff controls.

Mini Joystick

Mini Joystick for a power wheelchair

Mini Joystick are usually much smaller than the standard wheelchair joystick.  They required less force to deflect or operate the joystick, which may be a low as 18g of pressure.  Like a standard wheelchair joystick most of them are proportional, so the more they are deflected the faster the chair will move.  However some joysticks are controlled by the pressure applied and do not deflect. To keep the joystick compact, buttons for the power, lights and actuators are not part of the joystick housing, as these controls are operated by alternative methods.  Mini joysticks may activate a mode change on pushing directly down on the joystick from neutral position.

Touchpads

Touchpad controller on power wheelchair

Touchpads feel similar to what you may find on a computer for controlling its mouse cursor.  They are based on touch and no pressure is required.  Touchpads can be configured for the user so that touching a specific part of the touchpad relative to the center will move in that direction.  Alternatively it can be operated by dragging a finger along the touchpad in the desired direction.  An earlier blogpost explains this in some more detail, http://www.atandme.com/?p=674

Switches

Head switches on power wheelchair

Switches by their nature do not have proportional control.  So activating a switch will move in a particular direction and releasing the switch will stop.  However as a power wheelchair’s acceleration and deceleration characteristics can be setup to be gradual, driving can still be smooth.  Switches can be mechanical momentary switches or based on proximity where no physical contact is required.  Multiple switches can be used, one for each direction, three switches as in a head array or a single switch that is used with some scanning display.

Sip and Puff Controls

User in power wheelchair driving with sip and puff controls

These are operated by sucking and blowing on a mouthpiece.  Sip and puff pressures are programmable and will also have a mode change feature in order to operate other chair controls such as lights or actuators.  They require quite a bit of practice by the user to get good at driving.  Not only does the wheelchair electronics distinguish between a sip and a puff, it can also recognize the strength of the sip and puff.  Basic Sip and Puff pressure is interpretation as… HARD PUFF – Forward, SOFT PUFF – Right, SOFT SIP – Left and HARD SIP – Reverse.

In some cases, it may be necessary to also connect an emergency stop switch.  The stop switch needs to be mounted in a position for easy activation by the user.

Further details can be found from the following supplier websites.

Adaptive Switch Laboratories

Switch It

mo-Vis power wheelchair accessories

Dynamic Controls secondary controls

 

Turn your wheelchair’s joystick into your mouse

Turn the joystick of your wheelchair into a mouse to control your computer, compatible tablet and smartphone with the BJOY Ring.

The BJOY Ring is placed over your wheelchair’s original joystick.  It detects deflections in the joystick and translates this into cursor movement on any of the connected device.  External switches can be used for the mouse click.  By using a circular gesture of the joystick this will change control over to another connected device.

The BJOY Ring comes with software that allows you to modify the mouse operation features such as the pointer speed, orientation or buttons functions.  All the settings are stored on the BJOY Ring so there is no need to reconfigure the mouse when connecting to a different device.

See more information

Mounting Tablets using Ram Mounts

There are various modular mounting systems available to mount portable device onto wheelchairs.  For example you can use Daessy, Stem, Rehadapt, Mobilia or Mount’n Mover to build customised solutions to meet your needs.

Another mounting system that is more associated with mounting tablets and phones into cars and motor cycles can also be considered to mount these devices onto wheelchairs frames.

Some of the Ram Mounts parts used within the video are the,

X-Grip I, X-Grip-II and X-Grip III,
Double socket short arm for 1″ ball
Long double socket arm for 1″ ball
Flex arm 9″ long with NPT thread
6″ long pipe with NPT tread
Windshield mount base
Small tough clamp
Double U-Bolt base
1″ ball base with 1/4″ -20 threaded hole
1″ ball camera base with 1/4″ -20 threaded stud