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

3.1 Refining MDE Definition and Committee Scope

As noted in Section 1.1, the statutory authority of the MDE Advisory Committee limited its scope to medical equipment used for diagnostic purposes by adults. Therefore, from the outset, Committee members recognized that their deliberations would exclude considerations relevant to children and youth and medical equipment used for therapeutic or treatment purposes only rather than diagnostic testing (see Sections 7.1 and 7.2). Although differentiating between equipment intended for diagnostic versus therapeutic uses seems initially straightforward, during the first meeting (September 27-28, 2012), Committee members raised concerns about the exact equipment encompassed by MDE. These comments posed examples of types of equipment where this distinction between diagnostic and therapeutic purposes seemed ambiguous. Therefore, the Committee began its activities by first addressing the critical question that would circumscribe its future deliberations: What is medical diagnostic equipment?

To identify the various categories of MDE, Committee members conducted an exercise aimed at eliciting a comprehensive listing of medical diagnostic equipment types. Table 3.1 lists the equipment types mentioned during this exercise. Although the vast majority of this equipment fit squarely within a general understanding of “medical diagnostic equipment,” some items (marked with a superscript “a” on Table 3.1) appeared more ambiguous or their applicability for the proposed rules seemed unclear. Examples of considerations raised by equipment marked with the superscript “a” include the following:

Table 3.1

MDE Advisory Committee Preliminary List of
Potential Medical Diagnostic Equipment Types

 a Equipment types discussed to determine whether covered by proposed accessibility standards

During the initial Committee exercise mentioned above (to identify potential MDE types), Committee members explained their rationales for including or excluding various categories of equipment. Examples of this discussion include the following:

• Persons undergoing hemodialysis often sit in chairs configured to facilitate circulatory system access (e.g., through an arteriovenous fistula) and ensure patient comfort and safety during the procedure. Hemodialysis is explicitly therapeutic (i.e., a treatment). However, over the course of dialysis sessions, which can last for several hours, patients are monitored to identify potential complications that require immediate attention. This monitoring could be viewed as diagnostic.

• Operating room tables are typically used for surgeries that definitively treat or significantly palliate disease. However, surgery can be required to make a diagnosis (e.g., to get tissue for pathological evaluation to determine the presence of cancer). Sometimes operations that begin with therapeutic intent conclude as diagnostic or prognostic (e.g., operations aiming to remove cancerous tumors end when surgeons find the tumor has spread too widely to remove; in these situations surgeons often close the incision, having found evidence that will inform the patient’s cancer prognosis). Whether for therapeutic or diagnostic surgery, however, virtually all patients are transferred onto the operating room table by clinical staff from a stretcher after being transported from a pre-operative area where they likely received initial sedation. Since almost no patients get themselves onto operating room tables, it is not necessary to produce accessibility standards for tables in sterile operating room settings.

• Stretchers or gurneys are typically seen as transport equipment, used to move recumbent patients within inpatient facilities, emergency departments, and other health care delivery settings where patients require supine transport. Although clinical personnel frequently transfer patients to stretchers,^U in many instances patients get onto stretchers independently. Furthermore, sometimes patients undergo extensive diagnostic evaluations while on these stretchers (e.g., in emergency departments). Differentiating stretchers used exclusively for transportation versus diagnostic evaluation is possible. But questions arise about the practicality of having different types of stretchers with different capabilities in busy health care institutions where efficiency and ease of use are at a premium.

• Hospital beds serve the same basic function as do ordinary beds, but these beds often have specific features to address needs of both patients and staff (e.g., controls to raise and lower the head and foot areas, controls to raise and lower the height of the entire bed, mattresses with circulating air to prevent pressure ulcer development). Patients lying in hospital beds sometimes receive diagnostic testing: routine phlebotomy is a common example. But overall, relatively little diagnostic testing is performed while patients are in hospital beds.

• To get ultrasound testing or pulmonary function testing, patients must have access to the equipment. But often the ultrasonography or pulmonary function testing equipment is in a unit next to the table, stretcher, or chair where the patient is lying or sitting. In these circumstances, the focus should be on accessibility of the table, stretcher, or chair rather than on the MDE itself. For instance, the ultrasound transducer is easily moved to the patient, wherever the patient is.

• Exercise stress testing equipment, such as treadmills or stationary bicycles, are used for diagnostic purposes (i.e., to diagnose potential coronary insufficiency, angina, or other heart ailments). However, it is questionable whether this testing would be used for persons with physical disabilities who would not be able to perform the required physical activities (walking or jogging on the treadmill, riding the stationary bicycle). For some patients, stimulating cardiac stress through other forms of exercise (e.g., hand cycles) might be possible. But there are a variety of ways to diagnose coronary artery disease for all patients, regardless of disability. For each individual patient, regardless of disability, a variety of factors might affect the choice of diagnostic tests.^V These decisions are made by patients in consultation with their physicians and reflect individual personal and clinical circumstances and patients’ preferences.

Although this “naming” exercise helped clarify the potential range of MDE, Committee members still felt they needed more explicit guidance to define MDE appropriate for setting accessibility standards. A subgroup of Committee member agreed to develop a screen for identifying MDE for making accessibility standard recommendations, which they presented at the outset of the second day of the September 2012 meeting. They started with the definition of “medical device” used by the Food and Drug Administration (FDA, Box 3.1). The proposed screen for MDE for Committee consideration has five components as follows:

1. Is the product a medical device?

2. According to its Instructions for Use (IFU), does the medical device perform a diagnostic function?

3. Must patients interact physically with the medical device in order for the device to perform its diagnostic function?

4. Must the medical device interact physically with patients (e.g., support the entire patient or anatomical regions of the patient) in order for it to perform its diagnostic function?

5. Is there an equivalent means of facilitation that meets current standards of care for performing the diagnostic test?

Questions 1-4 must be answered in the affirmative and Question 5 must be answered in the negative for a product to be considered under the requirements of the proposed rule.

Throughout the remainder of its tenure, the Committee continued to discuss the applicability of certain equipment types for the accessibility standards.^W The general sense of the Committee was that the standards they recommend (Section 5) cover the vast majority of MDE. Nonetheless, certain specific types of MDE might need additional attention in future rulemaking about accessibility standards (Section 8.2).

Box 3.1

Food and Drug Administration Definition of Device

SOURCE: U.S. Food and Drug Administration http://www.fda.gov/medicaldevices/deviceregulationandguidance/overview/classifyyourdevice/ucm051512.htm, accessed May 31, 2013.

Notes

^U For instance, when patients are severely ill and need to be transported within a facility, staff will transfer them from their beds to the stretcher.

^V A variety of clinical and other considerations affect the choice of diagnostic testing for coronary artery disease, including: urgency (e.g., imminent threat of a heart attack); prior history of cardiac disease and coronary interventions; comorbid health conditions; other health risk factors; the availability of testing facilities; and patients’ preferences. The Advisory Committee did not consider the relative effectiveness of these different diagnostic approaches.

^W The proposed standards do not cover a few categories of equipment that may assist persons with disabilities in transferring onto or off of medical diagnostic equipment. Ancillary equipment, such as cushions, bolsters, straps, or sliding boards, can be used to facilitate transfers and to help position patients on medical diagnostic equipment. Lifts also can be used for transfer, although transfers performed with lifts are not independent. Because ancillary equipment and lifts do not perform any diagnostic function, they are not covered by the proposed accessibility standards.