The MDE Standards provide the minimum accessibility specifications for diagnostic equipment used in medical settings. As in the proposed Standards, the final rule organizes accessibility requirements into four types of patient positions that the diagnostic equipment is designed to support: (1) supine, prone, or side-lying position; (2) seated position; (3) seated in a wheelchair; and (4) standing position. The rationale for organizing the requirements in this way—rather than by specific type or function of equipment, for example—is that medical diagnostic equipment is typically designed to support patients in specific positions for examination. For example, an ophthalmology chair is designed to be used while the patient is in a seated position. A stand-on weight scale is designed to be used in a standing position. Some types of equipment are designed to be used in more than one position; for example, a fluoroscopy machine may support patient use in prone and standing positions. Equipment that supports patients in more than one position generally must conform to the requirements for each position in which it is designed to support patients.

Table 1 below summarizes the features that make equipment covered by the MDE Standards accessible. For each of the four patient positions of equipment covered by the Standards, the table indicates the features that make that category of equipment accessible (when the accessibility features are provided consistent with the technical specifications for each feature as stated in the Standards). The last column of the table gives examples of the types of equipment that fall into each category. The types of equipment listed in the last column are meant to be illustrative, and not exhaustive.

Table 1: Summary of Accessibility Features of MDE Standards, by Funcational Category of Patient Position(s) Supported by Equipment

 Patient Position Supported by the Equipment MDE Standards – Summary of Accessibility Features   Illustrative Equipment Types
Supine, prone, or side-lying position 
Transfer surface, including adjustability, size, and unobstructed transfer 
Transfer supports, leg supports, and head and back support 
Lift compatibility 
Examination tables
Imaging equipment designed for use with platform beds, such as a CT scanner
Radiology tables
Seated position 

Transfer surface, including adjustability, size, and unobstructed transfer

Transfer supports, leg supports, and head and back support

Lift compatibility


Examination chairs

Imaging equipment designed for use with a seat

Chair scales

Seated in a wheelchair (M303) 

Space for the wheelchair within the equipment; minimal slope of the wheelchair surface; edge protection of the wheelchair surface; beveled or ramped entry 

Same orientation to equipment as non-wheelchair users would orient

Knee and toe clearance within or below the equipment

Components capable of examining body parts of patients seated in a wheelchair, including breast platforms

Imaging equipment designed for wheelchair use

Weight scales designed for wheelchair use

Standing position 

Slip resistant standing surface

Standing supports


Imaging equipment with a standing surface

Weight scales designed for use in a standing position


In addition, the final rule includes technical criteria for supports (see M305), for instructions or other information communicated to patients through the equipment (see M306), and for operable parts used by patients (see M307).

The final rule reflects some significant changes from the proposed standards. The Access Board made three general types of changes. The first type of changes aimed to make diagnostic equipment as accessible and usable as possible for patients with disabilities. For example, the MDE Standards not only specify the minimum and maximum height of transfer surfaces of equipment used by patients in a seated position, but now also require additional adjustability within the minimum and maximum height range. A second set of changes incorporates well-known and relevant accessibility requirements in the Americans with Disabilities Act (ADA) and the Architectural Barriers Act (ABA) Accessibility Guidelines, to allow for easier implementation of the MDE Standards in the future. In the final rule, for instance, the technical requirements for transfer supports track ADA and ABA Accessibility Guidelines provisions related to the shape and size of a grab bar. Finally, the third type of changes ensures that the Standards do not compromise functionality and safety of the equipment while they seek to increase accessibility. To that end, the MDE Standards allow a number of general and specific exceptions, and they further clarify certain technical criteria such as knee and toe clearance for mammography equipment. A detailed discussion of all the changes made to the proposed standards can be found in the Preamble and Section-by-Section Analysis accompanying the final rule text.