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

5.3.1 Permitted Obstructions to Transfer Sides for M301 and M302

Description: Transfer side provisions are the same for M301 and M302 and require the transfer surface to be located to provide options to transfer onto the short side and the long side of the surface. The provisions result in the transfer surface being located at a corner of the equipment and the two transfer sides adjoining at the edges of the equipment. The provision will coincide with the seat area design of most examination chairs.

NPRM Proposed Provision: M301.2.3 and M302.2.3 Transfer Sides. The transfer surface shall be located to provide options to transfer from a mobility device onto one short side (depth) and one long side (width) of the surface. Each transfer side shall provide unobstructed access to the transfer surface.
EXCEPTION: Temporary obstructions may exist where they can move out of the way to permit transfer.

NPRM Preamble Discussion: The Access Board is considering whether the final standards should permit equipment parts to extend horizontally 3 inches maximum beyond the edge of the transfer sides provided they do not extend above the top of the transfer surface. This would allow handholds and other features that may facilitate transfer to be located on the transfer sides. The 2010 Standards provide a gap of 3 inches between the edge of a shower seat and the shower compartment entry, and the gap does not appear to interfere with transferring onto and off the shower seat.

The Committee recommends a 3-inch maximum obstruction permitted at transfer sides.

Rationale for the recommendation

Transfer supports provide handholds on adjustable medical equipment to facilitate transfers onto and off the equipment. Some medical equipment types have components that create a gap between the transfer surface and the outer edge of the equipment on the side used for transfer. This standard places a limit on the size of the gap allowed.

To address this, the Committee used the provisions in the 2010 Standards on shower compartment seats. These seats allow a maximum of a 3-inch gap between the edge of a shower seat and the shower compartment entry.

The Committee considered anthropometric data from a research project that examined transfer experience with an adjustable height transfer surface. The two surfaces were placed at the same height and subjects transferred at gaps in increments of 3.5 inches. The result showed that 95% of subjects could transfer when seat and surface are at same height with a 3.5-inch gap. This data helped inform the recommendation since the 3-inch criteria is less than that used in the research and should assure effective transfers for most.

Figure 5.3.1 Permitted 3-Inch Maximum Obstruction at Transfer Side
(SOURCE: U.S. Access Board)

The 3-inch gap would accommodate a variety of supports including ones foldable, collapsible, removable, and articulating. A common example of an obstruction is the side rails on stretchers. Arm rests and footrests are examples of permitted temporary obstructions because they move out of the way of the transfer. The 3-inch maximum gap applies to two sides of medical diagnostic equipment with a rectangular shape, the long length (width) and the short length (depth), where the transfer surface is located.

Special considerations for Stretchers

Each transfer side shall minimize obstructions to the transfer surface. Obstructions shall not be vertically less than 1 inch nor be horizontally more than 3 inches from the edge of the patient support surface to provide unobstructed access to the transfer surface.

This provision incorporates the provisions of IEC 60601-2-52 establishing the maximum vertical obstruction at no less than 1 inch below the top of the transfer surface.