Recommendations on Standards for the Design of Medical Diagnostic Equipment for Adults with Disabilities, Advisory Committee Final Report

A MINIMUM HIGHEST POINT STANDARD OF 19 INCHES IS CONSISTENT WITH EXISTING ACCESSIBILITY STANDARDS

Current accessibility standards and regulations generally consider a transfer surface with a fixed height between 17 inches and 19 inches accessible. Therefore, under these rules a transfer surface with a fixed height of 19 inches meets the definition of accessibility.¹¹

Nineteen-inch water closet and toilet seats are accessible:

604.4 Height. The height of water closet seats shall be 17 inches (430 mm) minimum and 19 inches (485 mm) maximum above the floor, measured to the top of the seat. Seats shall not be sprung to return to a lifted position.¹² 

Likewise, 19 inch high benches are accessible:

903.5 Height. The top of the bench seat shall be 17 inches (430 mm) minimum and 19 inches (485 mm) maximum above the floor, measured to the top of the seat.¹³ 

Nineteen-inch high bathtub seats are accessible:

610.2 Bathtub Seats. The height of bathtub seats shall be 17 inches (430 mm) minimum and 19 inches (485 mm) maximum above the bathroom floor, measured to the top of the seat. Removable in-tub seats shall be 15 inches (380 mm) minimum and 16 inches (405 mm) maximum in depth. Removable in-tub seats shall be capable of secure placement. Permanent seats shall be 15 inches (380 mm) minimum in depth and shall extend from the back wall to or beyond the outer edge of the bathtub. Permanent seats shall be positioned at the head end of the bathtub.¹⁴ 

Nineteen-inch high shower compartment seats are accessible:

610.3 Shower Compartment Seats. The height of shower compartment seats shall be 17 inches (430 mm) minimum and 19 inches (485 mm) maximum above the bathroom floor, measured to the top of the seat. In transfer-type and alternate roll-in-type showers, the seat shall extend along the seat wall to a point within 3 inches (75 mm) of the compartment entry. In standard roll-in-type showers, the seat shall extend from the control wall to a point within 3 inches (75 mm) of the compartment entry. Seats shall comply with Section 610.3.1 or 610.3.2.¹⁵ 

Nineteen-inch high amusement park rides are accessible:

1102.5.2 Transfer Height. The height of amusement ride seats designed for transfer shall be 14 inches (355 mm) minimum and 24 inches (610 mm) maximum measured from the surface of the load and unload area.¹⁶ 

As mentioned above, a minimum standard of 19 inches at the highest point of a table or chair is not the same as the transfer surface height experienced by patients because the front edge of currently available tables is lower than the highest measured point. However, the fact that a 19 inch height is so widely accepted by existing accessibility standards for various types of benches and chairs strongly commends maintaining the standard for medical diagnostic equipment as the minimum standard for accessible examination tables and chairs. This is particularly the case because of the manner in which medical diagnostic equipment is used. Toilets, bench seats, and bathtub seats remain at a fixed height for both transfer and normal use; in fact, usability of these devices may require constant contact of one’s feet with the floor for stability or require free use of one’s hands. Medical examination tables and chairs, on the other hand, are lowered to a low height to facilitate transfer, then are raised to a considerable height to facilitate medical examinations by the medical clinician.¹⁷ 

Finally, it is important to note the requirements for tolerancing under current regulations:

104.1.1 Construction and Manufacturing Tolerances. All dimensions are subject to conventional industry tolerances except where the requirement is stated as a range with specific minimum and maximum end points^.18 

In practical terms, because the low adjustable height is intended to be specified as a maximum dimension, manufacturers of accessible MDE will design their equipment not to exceed this maximum. Thus equipment designed to this standard will be, on average, less than the maximum allowed low adjustable height (e.g. 19 inches) by a height of conventional industry tolerances. These tolerances can be 1/4" or more, depending on the type of equipment.

NOTES

^11. Although the current accessibility standards and regulations described here reference a fixed height, the MDE advisory committee has recommended adding adjustable height to further enhance accessibility for users whose WMD’s are higher than 19 inches. This includes most power wheelchair and scooter users, as described in the AWM Project. Note that the accessibility standard for pool lifts, 1009.2.4, also specifies adjustability, but with a very different range of motion due to its intended use of lowering a person down into a body of water. 

^12. See Accessible and Usable Buildings and Facilities, ICC/ANSI A117.1-2009. Emphasis of upper dimension of range added.

^13. Ibid.

^14. Ibid.

^15. Ibid. 

^16. Ibid.

^17. Because medical table and chair are typically raised in height for a clinical examination, the transfer supports described in the proposed standards may provide the added benefit of patient security and stabilization.

^18. See Accessible and Usable Buildings and Facilities, ICC/ANSI A117.1-2009.