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Electronic Aids to Daily Living (EADLs)

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EADLs, also known as Environmental Control Units (ECUs), are devices used by individuals with mobility impairments to manipulate one or more electronic devices. EADLs are particularly useful for individuals with quadriplegia.

Essentially any device that can be controlled electronically can be controlled via an EADL, including

  • lights
  • televisions
  • stereos
  • doors
  • curtains
  • hospital beds
  • heating and air systems
  • fans
  • telephones
  • computers
  • alarms

EADLs can be used in a variety of settings; they allow persons with physical limitations to participate in everyday activities at home, the office, classroom, or health care center. EADLs offer the benefits of improved quality of life, reduced energy expenditure, increased vocational opportunities, positive psychosocial impact, and increased independence (Craig et al 2004; Rigby et al 2005, 2010). EADLs can be adapted for control by any individual, as long as that person can perform a consistent voluntary action.

Choosing the Right EADL

Selecting an EADL is an individualized decision and must be based on the user's unique needs. Information to take into consideration when choosing an EADL includes (Little 2007)

  • what devices the user wants to control
  • the location where the EADL will be mounted
  • how the EADL will be accessed
  • whether training with the EADL is available
  • gadget-tolerance level of the user
  • stability of the user’s condition
  • cognitive and physical abilities of the user
  • funding resources

Product Variability

EADLs range from relatively simple (i.e., controlling one device) to very complex (i.e., controlling twenty devices with hundreds of functions). EADLs may be wired or wireless and come in many different formats. They may rely on personal computer software or may be stand-alone. Computer-dependent systems allows for a higher degree of complexity in the programming of the EADL, but are more vulnerable to problems that can plague computers and are less portable. Stand alone units contain their own mechanics and electronics for operating, and therefore do not rely on a computer. Cost generally increases with the complexity of the EADL, with the exception that computer-dependent systems are usually cheaper than most stand alone EADLs. These may range from under one hundred dollars to several thousand dollars (Little 2007). Most EADLs provide the user with visual and/or auditory feedback to guide the user during use.

Using An EADL

In order for an EADL to be effective, it must be accessible (acknowledging the standards of the user) and easy to use. Four main elements go into successfully operating an Environmental Control Unit: the input method, the menu, the processor, and the activity output.


The input is what links the user to the processor. Users can provide input to an EADL via direct or indirect access. Direct access occurs when users control the EADL using setups including those such as touch screens or multiple-button keyboards. Indirect access occurs via voice or switch. Voice control enables the user to speak commands to the EADL. Switch access includes a variety of input options, such as a single push-button, an eye-gaze receiver, a sip-n-puff straw, or electroencephalography (EEG), and allows users to select options via virtually any voluntary action that can be consistently performed. Many EADLs offer more than one access method (Craig at al 2004, Little 2007).


The menu is generally a visual or auditory interface that is responsible for communicating with the user. This is where the user can select options for future commands, execute commands, and check the current status of the unit. Choices must be presented in an understandable and intuitive way so that the user knows his or her options at all times


The processor conducts the unit and coordinates all other elements with each other. It is responsible for understanding the user's inputs and forming those commands into an action. It then takes this action, creates the proper execution statement, and communicates this to the device which the user is trying to control. The processor is in charge of anything electronic in the device, and therefore, it also keeps the menu running and available for the user.

Activity Output

The activity output is the targeted device executing whatever commands the processor sent it. This part of the process includes any and all devices being controlled by the unit and anything else needed to carry out its command (Patti et al).

Transmission Technology

Technology utilized by EADLs includes wiring, ultrasound, infrared, and radio frequency; X-10 technology used to also be in use, but has since been discontinued. Two or more of these technologies are often combined in one device, or accessories may be purchased to increase an EADL’s compatibility with multiple transmission technologies.


House wiring is a common way to connect the house appliances and modules to the ECU. This is generally a convenient option for most as installation is comparatively simple and cheap. Using house wiring to connect the unit to the module can create difficulty in transportation with its lack of portability.


Ultrasound transmission works by sending sound frequencies from the unit to the appliance module as its mode of communication. Frequencies above around 40,000 Hz are used, which is well the capacity for humans to hear. This method has its advantages in that it is very portable and works at great distances, but the sound waves can easily be disrupted by solid objects or other sound waves.

Infrared (IR)

Infrared light transmission is commonly used in remote control of consumer electronics, and is utilized by EADLs to control televisions, stereos, dvd players, and more. One drawback of IR technology is the need for an unobstructed path between the remote and the receiver, with a limited distance of signal transmission. A useful feature of many IR systems is the option to combine multiple functions and control multiple appliances with a single EADL (Craig et al 2004).

Radio Frequency (RF)

Radio Frequency waves is a common transmission method and is often seen in garage door openers and cell phones. RF technology has a couple of advantages over IR technology, in that its signal can pass through barriers such as walls and floors, and its signal reaches farther than IR in most cases. Most RF systems require an RF base, a centralized piece of equipment in the building that receives signals from the EADL and passes them on to the devices being controlled. IR signal can be transformed into RF signal for more versatility. One downside to RF technology is that waves can interact with each other and distort one another.


X-10 technology has been discontinued by its manufacturer, but information about the product is included below.

X-10 technology is named for the company that patented the protocol behind this technology. X-10 can be used to control devices such as lights, fans, thermostats, beds, and doors. It primarily controls devices with only on/off functions. X-10 uses a building’s existing outlets and wiring, giving it the advantage of being easy to set up and install. A user can send a wireless signal to an X-10 transceiver, which sends the signal to a module attached to the device being controlled (light, fan, etc.). A separate module is needed for each device controlled (Little 2007).

Product Examples

REACH by Break Boundaries. Switch or voice access. X-10, IR, and RF. Controls many devices.
REACH by Break Boundaries. Switch or voice access. X-10, IR, and RF. Controls many devices.
Mini Relax by Ablenet. Scanning switch access. IR only. Controls up to six functions of one appliance.
Mini Relax by Ablenet. Scanning switch access. IR only. Controls up to six functions of one appliance.

External Links


  • Craig A, Tran Y, McIsaac P, Boord P. The efficacy and benefits of environmental control systems for the severely disabled. Med Sci Monit. 2005 Jan;11(1):RA32-9.
  • Little R. Electronic aids for daily living. J Rehabil Res Dev. 2007;44(5):vii-ix.
  • Rigby P, Ryan SE, Campbell KA. Electronic aids to daily living and quality of life for persons with tetraplegia. Disabil Rehabil Assist Technol. 2011;6(3):260-7. Epub 2010 Oct 1.
  • Rigby P, Ryan S, Joos, S, Cooper B, Jutai JW, Steggles I. Impact of electronic aids to daily living on the lives of persons with cervical spinal cord injuries. Assist Technol. 2005 Fall;17(2):89-97.
  • Patti Lindstrom, Ghassan Souri. Everything You Need To Know About Environmental Control Units. Disability Information Resources. 1998 February 24.