Integrating computer access and environmental control

The Assistive Technology Team have worked with Susan since 2006. When we first met Susan she was finding computer use with a standard mouse and keyboard very difficult and eventually this became impossible. She was also struggling to control other equipment around her house.

As this video shows, Susan is now able to control her computer, her door, phone, TV and other equipment, all using her head!  As with most people, this set up evolved over a period of time, as she tried different options and also as Susan’s condition (Multiple Sclerosis) changed.  The rest of this post describes her journey and how the equipment was set up for Susan.

After first meeting Susan, we installed an environmental control  system (a Possum Vivo) to enable Susan to control an intercom and lock for the front door, TV, lights, profiling bed and phone. Susan controlled all of this from a single hand operated switch. We tried a number of different computer access methods with Susan, but at that time the main alteration Susan needed was to change the position of her keyboard.

Although the switch could be operated by a small movement, Susan’s hand control reduced further, to the extent that access with this method became unreliable. Susan had the support of her local Occupational Therapist and when realising that the switch was becoming difficult they got back in touch with the team and requested a reassessment.  At this point we explored the use of alternative switches, potentially for computer and environmental control (EC) access.

After this period of trials Susan and the team agreed that a head worn sip and puff switch was the best option. The sip and puff switch could be used to produce mouse clicks or to operate a scanning on screen keyboard. The same method could also be used to control a software mouse emulator but she preferred a faster, more direct method for mouse control. We had trialled two main types of head tracking device – a free program called CameraMouse combined with her laptop’s built in webcam and making mouse clicks with the sip and puff switch. This worked reasonably well but as Susan could not access the standard keyboard or mouse there were difficulties with independently setting the camera up if it lost sight of her. The second method we tried for tracking head movement was a head-mouse. This is an infrared camera which tracks a small reflective dot placed on her forehead.

Susan was, and still is, able to accurately move the mouse cursor with the head-mouse and perform left and right mouse clicks using the sip and puff switch. Susan also uses a free on screen keyboard called Click N Type, which enables Susan to write emails and search the web.

Susan uses the sip and puff switch to access both her laptop and Possum Vivo and to be able to switch her focus between each device independently. This has been achieved with an ‘integrator’. The integrator has been designed and built by Graham, our team’s Electronics Technologist. Changing from computer to EC for example is achieved by sustaining a long sip (about 5 seconds in this case but can be adjusted). The sip and puff switch is then used to operate the EC. To revert back to using the sip and puff switch for computer use she has to maintain a sip for 5 seconds again. The integrator beeps to indicate a change of control from computer to EC and vice versa. A low battery warning is built in, but before the batteries fail the device will automatically set itself to controlling the EC so that she can still use the phone or open the door.

We inserted the sip and puff switch box, Joycable (computer switch connection box) and integrator into a single enclosure. This reduced the number of trailing leads and connectors, making it less daunting for her care staff to set up.

Susan is still successfully using this system to give her independence and control in her own home.

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