2.3 Specific Guidelines for Imaging Equipment

Overview

This specific guidance addresses imaging equipment, which was identified in the RERC-AMI's national consumer survey (Winters et al., 2007) and through focus groups (Story et al., 2009) as key equipment causing access barriers to healthcare services. Imaging equipment include devices used for a wide variety of examinations and procedures, including x-ray, mammography, MRI, CT and PET scanning, fluoroscopy, ultrasound, bone density scanning, radiation therapy, and nuclear medicine. This guidance also applies to imaging equipment installed in mobile facilities (e.g., trailers). The primary focus is on patient support surfaces for imaging equipment, which will be called the imaging platform.

The specific guidance provided here is based on existing legislation [Americans with Disabilities Act Accessibility Guidelines (ADAAG)] and experience of and research conducted by RERC-AMI staff (Story et al., 2008).

Specific Guidance

2.3.1 The height of the patient platform should be adjustable.

Discussion: The table should adjust in height to suit the needs and preferences of patients with different needs and preferences, as well as the needs of medical professionals of different heights and who perform different procedures.

The preferred minimum height is 17 inches (43-48 cm, ADAAG), although this is not currently available for all types of imaging platforms. The 17-inch height makes it possible for some wheelchair users to transfer themselves onto the platform from the wheelchair and for some people of short stature to use the platform independently.

However, some wheelchair users and ambulatory people may prefer to have the platform at a higher height (e.g., 19-20 inches or 48-51 cm) when getting off the platform. It is easier for wheelchair users to transfer themselves off a platform that is higher than the seat of the wheelchair (so they are working with the force of gravity rather than against it), and it is easier for individuals with weaker quadracep (thigh) muscles to stand up from a higher seat (Demura & Yamada, 2007).

2.3.2 The weight lifting capacity of height-adjustable imaging platforms should be at least 400 lb.

Discussion: A 400-lb. capacity to lift patients while they are on the table will accommodate more than 99% of the U.S. population.

In 2003-2004, the CDC’s National Health and Nutrition Examination Surveys (NHANES) found that 32.2% of Americans age 20 and older (31.1% of men and 33.2% of women) were obese (body mass index or BMI ≥ 30.0) and 2% of Americans were morbidly obese (BMI ≥ 40.0). In the U.S., 5% of adult women (aged 20 years and older) weighed more than 243.0 lbs. (110.2 kg; BMI ≥ 41.5) and 5% of adult men weighed more than 267.1 lbs. (121.2 kg; BMI ≥ 37.6) (National Center for Health Statistics, 2006). However, because obese individuals are overrepresented in primary care (Stecker & Sparks, 2006), medical facilities should be prepared to accommodate larger individuals, including people who weigh much more than 400 pounds.

2.3.3 A 1-step device with railings on both sides should be provided for all radiology platforms that are 24-30 inches (61-76 cm) above the floor and not height-adjustable. A 2-step device with railings on both sides should be provided for all radiology platforms that are taller than 30 inches (76 cm) and not height-adjustable.

Discussion: Depending on the specific product used, a step device will reduce the effective height of the platform to 17-24 inches (43-61 cm), which is easier for patients to sit down on and stand up from. On 2-step units, the heights of the steps should be identical. The leading edge of each step should be marked with a color that visually contrasts with the step tread. The steps should have no sharp edges.

2.3.4 Any pad or cushion on the surface of the platform should be firmly attached or secured in place.

Discussion: The platform’s padding or cushion should be firmly secured in place so as not to endanger the stability of patients while transferring onto and off the equipment or while repositioning themselves. If the pad is not secured, patients are put at risk of losing their balance, sliding and falling.

2.3.5 The stiffness of the platform padding or cushion should be appropriate to the application.

Discussion: Softer surfaces are more comfortable and appropriate for platforms on which patients must remain for a substantial period of time but can more more difficult to transfer on and off, especially for wheelchair users and others who perform lateral transfers. In contrast, firmer surfaces are less comfortable but can be easier to transfer onto and may be appropriate for applications in which patients remain on the surface for only a short duration. More research is needed to investigate the optimal characteristics of transfer surfaces.

2.3.6 The platform should have handholds to improve patient safety and enhance independence while getting on or off the equipment.

Discussion: The handholds may be side rails, arm rests, grab bars, handles, vertical poles, or other elements that provide a secure grip for patients while maneuvering their bodies relative to the platform. Patients may use handholds while getting on or off the equipment, or while repositioning themselves while on it. Research is ongoing in this area.

2.3.7 Imaging equipment should be designed to minimize patient access to device components that may endanger their safety.

Discussion: Some imaging equipment components are designed for effective and convenient use by medical professionals but may be hazardous when used by medical patients. For example, the foot pedal at the base of an x-ray machine facilitates height adjustments made by the technologist but can put patients at risk of falling when they accidentally step on it while getting on or off the platform and it unexpectedly moves up or down underneath them. The handle on the scanning head of a fluoroscopy machine facilitates its placement by the attending technologist but can put patients at risk of falling when they grasp the unstable handle while stepping down from the footboard when the platform is in its vertical position. The handle on an x-ray plate of a fluoroscopy machine facilitates its insertion and removal from the machine by the technologist but can upset the balance of patients who grasp the handle for support and put weight on it while climbing onto the platform and the plate unexpectedly slides out toward them.

2.3.8 Except where technologically unfeasible, the platform should have side rails or armrests available. The side rails should drop down or be removable so they will not obstruct patient transfers or hinder professional diagnosis or treatment.

Discussion: Side rails or armrests enhance patient safety, stability, security and comfort while sitting on the platform or while repostioning themselves, especially when no healthcare professional is present. However, side rails may need to move out of the way when patients are getting on and off, depending on individual patient needs and preferences. They may also need to be removed to increase healthcare professionals’ physical access to the patient. The platform should provide a place to store the side rails (e.g., in a side recess or in a drawer on one end) so they will be readily available when needed.

2.3.9 The platform cushion should be wide enough to allow the patient to manuever safely and comfortably into any body position that may be needed or desired (e.g., lie on one side, roll over, shift pressure points).

Discussion: Wider widths make it easier for patients to position or reposition their bodies but wider platforms are not currently available for all imaging equipment.

2.3.10 The base of the machine should not extend past the edge of the patient platform or its cushion.

Discussion: A base that extends past the edge of the platform may prevent patients who use wheelchairs from maneuvering close prior to transferring, which may make the process less safe. The edge of any flat plate where the platform base meets the floor should be beveled or sloped so it will not be a tripping hazard or rolling obstruction. More research is needed to understand the base clearance needs of wheelchair users, including the needs of people who transfer laterally and those who transfer in a forward direction.

2.3.11 The machine should provide clearance for patient lift equipment.

Discussion: The base of the machine may be narrow enough for portable lift equipment to straddle one end, or it may have clear space underneath to accommodate the legs of portable lift equipment. The machine should allow a clear path of travel for overhead lift equipment, if applicable. Mechanical lifting equipment should be used for all patients who cannot stand or transfer themselves. Lifts enable safer and more secure transfers and protect medical staff from injuries associated with patient lifting.

2.3.12 A device to assist patients to sit up should be provided for imaging platforms on which patients lie down.

Discussion: Sitting up is a difficult task for some patients and can impose physical demands on the medical professionals who serve them. If compatible with the imaging technology, providing an overhead trapeze or side railings or other device that provides support for sitting up can be beneficial for many patients. It is important that these devices not introduce a hazard for other users, such as people with visual impairments who may encounter the device unexpectedly. This can be avoided by securing the trapeze out of the way when not in use.

2.3.13 Side railings or other effective handholds as well as strapping to secure patients against the platform should be provided for imaging platforms that rotate patients into a vertical position (e.g., fluoroscopy).

Discussion: People with impaired balance find it difficult to stand on the footboard of an imaging machine while it rotates between horizontal and vertical. Side railings can enhance patient stability and security and, because of their length, offer patients a choice of grip location. Strapping, such as strips of woven material with velcro closures, can enhance patient stability, security, and comfort.

2.3.14 The opening in imaging equipment that a patient must pass through (e.g., the bore in a MRI and CT scan machine) must be large enough to accommodate patients with a waist size of at least 50 inches (127 cm).

Discussion: Imaging equipment should accommodate people with a variety of waist sizes. The 2003-04 National Health and Nutrition Examination Survey (NHANES) found that 5% of adult women had a waist circumference larger than 47.6 inches (120.9 cm) and 5% of adult men had a waist larger than 49.2 inches (125.0 cm) (National Center for Health Statistics, 2006).

2.3.15 On mammography equipment, the imaging receptors (tilt arm and bucky) should lower to a minimum height no greater than 24 inches.

Discussion: This height will accommodate people of short stature and allow patients who cannot stand to sit in a chair or wheelchair during a mammographic scan.

2.3.16 On mammography equipment, a mammography chair should be offered to patients who may have difficulty standing up for the duration of the scanning procedure.

Discussion: Not all patients are able to sustain a standing position for the amount of time required for mammographic scans; mammography chairs are available that have been designed to be especially adjustable and supportive for this purpose.

2.3.17 On mammography equipment, the space under the device should be open to provide knee and foot plate clearance for a patient seated in a wheelchair.

Discussion: Further research and development are needed in this area. No unit currently on the market has adequate knee and foot plate clearance for patients who use wheelchairs, that is, space between the machine pedestal and the outer edge of the bucky (breast support plate).

2.3.18 On mammography equipment, the compression paddles should be flexible.

Discussion: Flexible compression paddles are more comfortable and create more targeted compression, which may increase the likelihood of capturing usable images on patients with spasticity and/or difficulty remaining still for the duration of the scanning procedure.

2.3.19 With scanning equipment that requires the medical professional to leave the room (such as MRI, CT and PET), a communication system should be provided that is effective for the patient.

Discussion: Patients without hearing impairments may be able to use an intercom system. A call button may enable the patient to initiate communication with medical staff in the other room. Patients with hearing disabilities may be able to use graphics (e.g., cartoons and/or illuminated buttons or shapes) that indicate when they should hold their breath or when they may breathe normally. Patients with visual disabilities appreciate frequent verbal communication so they know what is happening during procedures.

2.3.20 Mobile imaging facilities (e.g., trailers) should have sufficient floor space to accommodate mobility and/or transfer devices (e.g., wheelchairs and gurneys) and transfer assistance, including lift equipment.

Discussion: Some patients are not ambulatory and use wheelchairs. These individuals must be transferred from the wheelchair or other mobility device (e.g., gurney) onto the imaging platform. Mechanical lifting equipment should be used for all patients who cannot stand or transfer themselves. Lifts enable safer and more secure transfers and protect medical staff from injuries associated with patient lifting.

TRAINING

2.3.21 Healthcare providers should be trained in how to serve patients with disabilities: e.g., how to transfer patients onto and off platforms, secure patients to platforms that rotate from horizontal to vertical, use auxiliary devices such as siderails, and communicate with patients with sensory disabilities.

Discussion: Patients with disabilities may need physical support to transfer on and off equipment, or assume or maintain body positions. This support may be provided by staff or with ancillary equipment. Patients may need assistance to navigate through a facility, They may need informational materials in alternative formats, such as large print or audio. They may need to communicate with staff in atypical ways, such as using light cues instead of speech during radiologic procedures for patients with hearing disabilities. Finally, patients with disabilities may need additional time for examinations and procedures. It is best to plan ahead and be prepared to accommodate individual patient needs.

2.3.22 For ambulatory patients, healthcare providers should set height-adjustable imaging platforms to the height of the patient’s mid-thigh for getting on and off.

Discussion: People with weaker quadracep (thigh) muscles find it easier to sit down and sit up from a seat that is taller than a typical chair (i.e., taller than 17-19 inches or 43-48 cm) (Demura & Yamada, 2007).

2.3.23 Healthcare providers should offer patients positioning aids appropriate to the situation.

Discussion: A variety of ancillary support devices should be offered to support and stabilize patients to maintain comfortably specific positions of their bodies, arms, legs, head, or other body parts, as needed. The ancillary devices may be foam wedges, shaped cushions, pillows, and/or straps (e.g., woven material with velcro closures).

References

Americans with Disabilities Act Accessibility Guidelines (2002). 28 C.F.R., Part 36.

Demura, S. & Yamada, T. (2007) Height of chair seat and movement characteristics in sit-to-stand by young and elderly adults. Percept Mot Skills, 104(1):21-31.

National Center for Health Statistics (2006). Prevalence of overweight and obesity among adults: United States, 2003-2004. Hyattsville, MD: U.S. Department of Health and Human Services, Centers for Disease Control and Prevention.

Stecker, T. & Sparks, S. (2006). Prevalence of obese patients in a primary care setting. Obesity, 14:373-376.

Story, MF, Luce, A, Leung, A, Omiatek, E, Lemke, MR & Rempel, DM (2008). Accessibility of radiology equipment for patients with mobility disabilities. Human Factors, 50(5), 801-810

Story, MF, Schwier, E & Kailes, JI (2009). Perspectives of patients with disabilities on the accessibility of medical equipment: Examinations tables, imaging equipment, medical chairs and weight scales. Disability and Health Journal, 2(4), 169-179

Winters, J.M.W., Story, M.F., Barnekow, K., Kailes, J.I., Premo, B., Schwier, E, Danturthi, S. & Winters, J.M. (2007). Results of a national survey on accessibility of medical instrumentation for consumers. In Medical Instrumentation: Accessibility and Usability Considerations, J.M. Winters and M.F. Story, Eds. Boca Raton: CRC Press, 13-28.