36 CFR Part 1195 Proposed Accessibility Standards for Medical Diagnostic Equipment NPRM - Preamble

M307 Operable Parts

M307 provides technical criteria for operable parts used by patients to activate, deactivate, or adjust the diagnostic equipment (see defined terms in M102.1). For example, equipment used for an auditory examination may require the patient to press a button when sounds are heard. M307 does not apply to controls used only by health care personnel or others who are not patients.

M307.2 would require operable parts to be tactilely discernible without activation. Patients who are blind or have low vision have difficulty distinguishing a flat membrane button or similar control unless it is tactilely discernible from the surrounding surface and any adjacent controls. The most common method to ensure that buttons and similar controls are tactilely discernible is to raise part or all of the control surface above the surrounding surface and at a distance from any adjacent controls such that a relief of each individual control can be determined by touch. This also prevents unintended or accidental activation of the operable parts. M307.2 is consistent with recommendations in ANSI/AAMI HE 75 that “features should be operable from controls that are tactilely discernible and that can be explored without being activated.” See ANSI/AAMI HE 75, section 16.3.5.5.

M307.3 would require operable parts such as dials, switches, and levers to be operable with one hand without tight grasping, pinching, or twisting of the wrist. M307.4 would require the force to activate operable parts to not exceed 5 pounds. M307.3 and M307.4 are based on provisions for operable parts in the 2004 ADA and ABA Accessibility Guidelines. M307.3 and M307.4 are also consistent with recommendations in ANSI/AAMI HE 75 that “devices should have at least one mode of use that does not require fine motor control or the performance of simultaneous actions.” ANSI/AAMI HE 75 includes additional recommended practices for accessible controls. See ANSI/AAMI HE 75, section 16.3.3.

The Wheeled Mobility Anthropometry Project recommended that “operable parts that require fine grips preferably should not require exertion of lateral pinch grip forces in excess of 2 pounds force to accommodate the vast majority of … users having at least some grasping capability.” The Wheeled Mobility Anthropometry Project recommended that the 5 pounds maximum force be retained for other types of operable parts. See Final Report of the Wheeled Mobility Anthropometry Project, page 105. The Access Board is considering requiring in the final standards that operable parts used by patients that require fine grips to not exceed 2 pounds maximum operating force.

Question 42. Comments are requested on the following questions regarding the operating force (2 pounds maximum) that the Access Board is considering requiring in the final standards for operable parts used by patients that require fine grips:

a) What would be the incremental costs for the design or redesign and manufacture of the equipment to provide operable parts that meet the above operating force?

b) Are there types of equipment that cannot provide operable parts that meet the above operating force because of the structural or operational characteristics of the equipment?

The 2004 ADA and ABA Accessibility Guidelines require that operable parts be placed within certain reach ranges. For an unobstructed forward reach or side reach, the reach ranges are 48 inches maximum for a high reach and 15 inches minimum for a low reach. ANSI/AAMI HE 75 provides guidance on reach ranges based on provisions in an earlier version of accessibility guidelines for buildings and facilities issued by the Access Board, the 1991 Americans with Disabilities Act Accessibility Guidelines (ADAAG). ANSI/AAMI HE 75 also recommends a remote control as an alternative to a direct reach. See ANSI/AAMI HE 75, section 16.3.2.2. The reach ranges in the 2004 ADA and ABA Accessibility Guidelines provide greater accessibility than the reach ranges in the 1991 ADAAG.

Question 43. Comments are requested on the following questions regarding reach ranges for operable parts on diagnostic equipment that are used by patients:

a) Would the reach ranges in the 2004 ADA and ABA Accessibility Guidelines for an unobstructed forward reach or side reach (48 inches maximum for a high reach and 15 inches minimum for a low reach) be appropriate for operable parts on diagnostic equipment that are used by patients?

b) Would alternative technical criteria be appropriate for reach ranges for operable parts on diagnostic equipment that are used by patients? Comments should include information on sources to support the alternative technical criteria, where possible.