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Assistive Technology Quick Reference Guide |
Mouse
Alternatives
Computer
Access Series |
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A computer mouse can be difficult for a person with a disability to use. The user needs to be able to grasp the mouse, move it around in a controlled fashion on a table, and often hold down a button while making these movements. The user also needs to be able see a mouse cursor on the screen and translate those arm movements into cursor placement.
Mouse alternatives are devices that may let a person move
the computer cursor more easily with his or her hand, or by not using hands at
all. They include trackballs, joysticks,
touchscreens, headpointers, and touchpads.
Microsoft and Apple both have utilities that set the number pad up so
that it can control cursor movements.
Some voice input systems can also be used to control the cursor. The products described in this article are
only a few of the many mouse alternatives available on the market today. The
companies listed may also make or distribute other products, and the included
resources also list additional products.
· Trackballs - A trackball works like an upside-down mouse. Instead of rolling the ball on the table by sliding the mouse around, the ball is moved directly by the user. The trackball does not need to be grabbed; only the ball must be nudged. Most people move the ball with their hands, but it can also be operated with a chin, elbow, foot, or stick held in the mouth. Trackballs come in many sizes, including ones that can be operated by a single finger. For people with limited fine motor ability, a trackball with a larger ball may be useful. Since the trackball remains in a stationary position on the desk or mounted on a stand, it can be a good option for a person with a limited range of motion. They are available at standard computer stores for $50-100.
· Joystick - A computer joystick operates a bit differently than a wheelchair joystick. Wheelchair joysticks usually operate as a set of switches, so how far or how fast you go does not depend on how far you push the joystick. For computers, how far a joystick is pushed does matter. For this reason, a person with spasticity who is able to use the all-or-none approach with a wheelchair joystick may have trouble with the more precise control required to use a computer joystick. Still, a joystick may be easier to grab than a mouse, it requires a smaller range of motion than a mouse, and it can also be operated by chin or mouth movements (Jouse). Joysticks range in price from $200-2200, depending on features.
·
TouchWindows / Touch Screens
- Touch
screens let a person point to parts of a monitor and make selections based on
where he/she touches. Since the person
points directly to what he wants, rather than moving a ball to move a cursor to
point to what he wants, it is cognitively easier to use. However, the user also needs to be able to
reach up to the monitor. Edmark's
TouchWindow is a device that fits over a monitor to add this capability
(about $350). Monitors with this feature
built in cost about $800-1700.
§
Digitizing tablet / touch
pads - To
operate a touch pad, a person moves his/her finger, or a stylus, around on a
flat tablet. The cursor moves in a
corresponding pattern on the screen.
This can be a good solution for a person who is not able to grasp a
device. Most touch pads require only a
small range of motion, and some are as small as a 2 x 2 inch square. They cost $40-70.
·
Head pointers - There are several types
of head pointers. One of the original
types consists of a helmet to which is attached a long rod. Keys are hit on a keyboard with this rod, but
this may not be a comfortable method of data entry and can transfer stress to
the neck. Newer head pointers are
electronic and move the cursor in response to head movements. They require the person to wear an infrared (Headmaster) or micro-gyroscope (Tracer) sensor on his head or perhaps a
reflective dot (Tracker, HeadMouse). The system measures signals from the sensors,
or looks at the way light reflects off the dot, to determine whether the user
is moving his head up or down, right or left.
The cursor is moved in the same direction as the user's head
movements. The result is a cursor
control method that is completely hands free.
Mouse clicks can be performed by activating a separate switch or by
holding the mouse position for a certain length of time (dwell mode). However, the user needs to have good head
control, some setup assistance may be needed to put on the reflective dot or
sensor, and these systems can be expensive (about $1000).
·
MouseKeys - MouseKeys is a feature
that is built into both Windows and the Macintosh operating system (therefore,
most computer owners already have it) to allow a person to move the cursor with
the number pad keys. For example,
"8" moves the cursor up, "1" moves the cursor to the lower
left, etc. MouseKeys provides a nice
cursor control option for people who type with a mouthstick or typing splint. It is slow, but it offers good accuracy for
times when a person needs to aim the cursor at a small target.
§
Eye Gaze and Eye Tracking - A mounted camera-like
device translates eye movements and eye stares ("dwelling")into
directing the on-screen mouse.
"Mouse clicks" are done with a slow eye blink, an eye dwell,
or a hardware switch. These systems are
not suitable for people with uncontrollable eye movement (nystagmus), and
potential users must be evaluated and approved in order to purchase the device. They can cost about $10,000.
For
problems with carpal tunnel syndrome, a wrist rest designed to be used with a
mouse may be tried. Sometimes, switching
hands can help. Mouse sizes vary between
brands and models, and a too small or too large mouse can be stressful to use
over time. Some mice are curved for a
better ergonomic fit. This may be more
comfortable, or could make the situation worse.
For example, people who are left-handed should not use right-handed
mice!
Some
people find that they have trouble using a standard keyboard, but are easily
able to use a mouse alternative. In
these cases, an on-screen keyboard might be tried in place of the standard
keyboard. A picture of a keyboard is
shown on the computer screen, and by pointing to a letter and clicking, the
letter is typed. The keyboard that is
shown may have a standard QWERTY layout, or it might have a different letter
arrangement, show words rather than letters, or be customized for an
application. Commercial on-screen
keyboards usually cost about $400.
The
NoHands Mouse from Hunter Digital has
two foot pedals: one pedal controls cursor movement, the other is for mouse
clicks. The standard desktop mouse remains connected and can be used at the
same time. Another option is an extra large trackball (i.e., Microsoft Easyball or Kensington Expert Mouse) combined with
foot pedals (i.e., Step-On-It!) for
the mouse buttons. The Step-On-It! keyboard control pedals can
be custom-programmed by the user to assign or reassign any three keys or mouse
clicks to floor operation. These products range from $100-290.
CameraMouse uses a camera to capture
images of the user’s head or face and tracks head movements by measuring
changes in that image. It can also track finger or toe movement.
PI Engineering's Y-Mouse allows a person to connect
two pointing devices to a PC at one time, with both remaining active. This allow a users to operate a pointing
device until they tire, then swap to the alternate device. It also allows one workstation to be shared
by two people who need different mouse control devices. It costs about $50.
A
normal cursor averages 16x16 pixels. RJ Cooper's Biggy software changes the
cursor size to 32x32 pixels and even 32x64 pixels. Different colors and shapes are used to
further enhance visibility. This
software costs about $100.
ITAC Systems and Microspeed both make trackballs for Sun workstations. Sun
Microsystems also makes a keyboard interface box so that PC equipment can
be connected.
Haptic
mice are a new invention that provides feedback to the user. The mouse or stylus is mounted on an arm that
provides resistance or vibrates as the cursor is moved over various lines on
the screen. Although there is not yet
much software that works with these devices, they may someday be useful for
people with visual impairments because of their potential to let the user
"feel" what is on the computer screen.
The Mouse List - http://www.setbc.org/mouselist/mousetop.html
Typing Injury FAQ: Pointing Devices -
http://www.tifaq.com/mice.html
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Bilbo Innovations |
Phone: 408-736-6086 |
http://www.bilbo.com |
Step On It! foot pedals |
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Boost Technology |
Phone: 415-334-8246 |
http://www.boosttechnology.com |
Tracer head pointer |
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CameraMouse, Inc. |
Phone: 972-231-1180 |
http://www.cameramouse.com |
CameraMouse motion tracker |
|
Cirque |
800-454-3375; 801-467-1100 |
http://www.glidepoint.com |
touchpads |
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Don Johnston |
Phone: 800-999-4660 |
http://www.donjohnston.com |
Penny & Giles
joysticks, trackballs |
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Edmark |
Phone: 800-691-2986 |
www.edmark.com/specialneeds |
Touch Window |
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EyeTech Digital Systems |
Phone: 480-610-1899 |
http://www.eyetechds.com |
Quick Glance Eye-tracking |
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HACH |
800-624-7968; 336-744-7280 |
http://www.hatchstuff.com/ products/assistive.html |
trackballs for children |
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Hunter Digital |
Phone: 800-57-MOUSE; 310-476-1874 |
http://www.footmouse.com |
No-Hands Mouse |
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Infogrip, Inc. |
800-397-0921; 805-652-0770 |
http://www.infogrip.com |
resellers |
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Keyboard Alternatives & Vision Solutions |
800-953-9262; 707-544-8000 |
http://www.keyalt.com |
resellers |
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Kensington Microware |
800-268-3447 |
http://www.kensington.com/ products/pro_c1018.html |
trackballs |
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Madenta |
877-623-3682; 780-450-8926 |
http://www.madentec.com/ products/products.html |
Tracker head pointer |
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Origin Instruments |
Phone: 972-606-8740 |
http://www.orin.com |
HeadMouse head pointer |
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P.I. Engineering, Inc. |
800-628-3185; 517-655-5523 |
http://www.ymouse.com |
Y-mouse |
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Prentke Romich Co. |
Phone: 800-262-1984 |
http://www.prentrom.com |
HeadMaster, Jouse joystick |
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RJ Cooper & Assoc. |
800-752-6673; 949-582-2749 |
http://rjcooper.com/site-map/ |
switch adapted devices, Biggy |