For purposes of ORS 316.752 to 316.771:
(1) A person has a “severe disability” if the person:
(a) Has lost the use of one or more lower extremities;
(b) Has lost the use of both hands;
(c) Is disabled as that term is defined in section 72(m)(7) of the Internal Revenue Code, to a degree that the person is unable to engage in any substantial gainful activity; or
(d) Has a physical or mental condition that limits the abilities of the person to earn a living, maintain a household or provide personal transportation for the person without employing orthopedic or medical equipment or outside help.
(2) “Orthopedic or medical equipment” includes, but is not limited to, wheelchairs, braces, prostheses or special crutches.
(3) “Outside help” includes, but is not limited to, unrelated individuals whom the taxpayer with a severe disability employs to keep house, maintain the house or yard, or to transport the taxpayer.