Technical Report AMI-MU-008:

Accessible Medical Beds

Authors: Christopher Zanoni

Coordinating Editor: Melissa Lemke, M.S.

Laboratory: Medical Device Accessibility and Usability Laboratory

Current Version: 1.0 (August 2006)

Table of Contents

Executive Summary

This report provides a survey of medical bed technologies, with special emphasis on accessibility features available for individuals with disabilities. Products in the following categories are evaluated here: regular beds, bariatric beds, home-style hospital beds, respiratory beds, and birthing beds. Medical beds range from fully manual to semi-electric to fully electric, and various medical beds that are currently available on the market are described in the product table and product survey presented here.

Of primary concern for healthcare providers is preventing back injuries that may be caused from tasks involved with using medical beds. Although proper training on the use of this equipment is often a cost effective-solution, many injuries related to patient transfers and repositioning of patients are still reported. Therefore, equipment improvements should be centered around minimizing the strain placed on both caregivers and patients who use medical beds. Two basic features that help reduce caretaker strain include an adjustable bed height and a transport mechanism (e.g., casters). Specialized medical beds (i.s., bariatric, respiratory, and birthing beds) each include features that are specifically designed to help patients with certain conditions. Home-style hospital beds often are designed for multiple-uses, and more control is given to the patient than with a bed that is used in a clinical setting.

Background

Medical beds are available in fully electric, semi-electric and manual models. The medical bed frame is generally made with strong lightweight steel and aluminum sections. The fasteners and moving parts are made of stainless steel. Plastic or metal is used for the siderail bars. Medical beds often have mechanisms for raising and lowering the height of the bed and to adjust the head and leg positions. Movement of the bed occurs vertically while rotation occurs in the back, seat and foot.

Back injury is prevalent among nurses and other caregivers which costs the healthcare industry $1.7 billion each year in workers compensation costs (http://www.nurseweek.com/news/features/01-01/back.asp). "Nurses are most likely to suffer a back injury where there are unpredictable responses from patients during ambulation or transfer, situations in which patients require constant lifting and turning, and in situations that require awkward positions while moving patients," said Kathleen McAndrew, MSN, NP, member of the Board of Directors of the American Association of Occupational Health Nurses (http://www.nurseweek.com/news/features/01-01/back.asp). Reducing the number of injuries should be of primary concern to hospitals and to nurses who wish to remain healthy and engaged in active patient care.

Because of the physically demanding nature of some patient lifting and positioning tasks, some hospitals have evolved to using “lift teams” who are groups of trained individuals who perform the lifting tasks involved with patient transferring throughout the entire facility (www.nolift.com). Injuries result most often from transferring patients from bed to chair or commode, lifting or repositioning in the bed and in routine bed making activities in which the patient remains in the bed (http://www.spineuniverse.com/displayarticle.php/article1509.html).

It should be noted that some caregivers may be aging or have a disability, and in some cases family members serve as primary caregivers, particularly in the home environment. Thus, it is important to design beds that are easy to use by untrained professionals who may have limitations in strength, range of motion, etc.

The following are current solutions that hospitals and medical bed manufacturers are using to reduce caretaker injury. Solutions range from training to advances in medical bed technologies.

Product Table

Approximately 40 products from 11 different manufacturers are provided for your reference. Click on the following links to view a list of the following types of hospital beds:

Note: If the height of the bed in the low position is greater than 19 inches it may not be accessible. Therefore beds that do not meet this criterion have been highlighted in yellow. However, due to the lack of consistencey in dimensional data, other beds not highlighted in yellow may also be inaccessible. Some measurements are taken from the floor to the bed deck while others are taken from the floor to the top surface of the mattress.

For an overview and instructions on how to navigate within the product table click here.

Product Survey

The product table displays various models and characteristics of regular, bariatric, home-style, respiratory, and birthing medical beds. The medical beds included within the table have at least one accessible feature to note. The table is organized with the bed categories grouped separately, and the vertical columns are used to display approximately 70 product characteristics. The following is a sample of the information included in the product table:

Product Evaluation

Regular Beds

In terms of the types of medical beds, this section is the least specific. It encompasses hospital beds that do no fall under bariatric, respiratory, or birthing hospital beds.

Medical beds are manually, semi-electrically powered, or fully-electrically powered. Older medical beds utilize the caregivers’ power and are thus either manual or semi-electric. Hospitals upgrade their own beds as needed. They have little incentive to replace functional beds just because the technology is outdated.

Invacare offers a product line of medical beds that are simple and lower cost. Invacare implements minimum features that come standard on all other medical beds (e.g. Trendelenburg, back adjustability, etc.). They offer the only fully manual hospital bed that is currently on the market, and a hand crank is used to adjust their manual hospital beds. This hand crank technology is used on all Invacare and SunTec hospital beds as a method to return the bed to a flat position in the event of power outage, which is a requirement stated in the IEC-60601-2-38 standard for hospital beds (52.5.102). Current methods used to adjust a medical bed without electrical power include a hand crank, release lever, or backup battery.

Two main features that help reduce caretaker strain are adjustable bed height and a transportable bed. The easier a bed can be adjusted, the more likely the adjustment will be used by the caretaker. Transferring a patient from one surface to another is among the most strenuous and risky maneuvers, and it is often required in healthcare settings. The easiest and safest transfer occurs when the heights of the two surfaces are equivalent, and another way to reduce work loads related to transferring is to avoid transferring the patient altogether. Thus, if beds are easily movable, the caretaker can just move the entire bed instead of moving the patient from a bed to a more mobile surface. Companies like Stryker and Hill-Rom have a power assisted drive that makes the task of moving patients in bed easier.

Patients getting caught, trapped or entangled in the gap between the mattress and side rail has caused 413 deaths and 278 injuries between 1985 and 2005 according to the FDA (http://www.fda.gov/cdrh/beds/bedrail.pdf). Reducing the space between the side rail and the bed minimizes this and provides safer patient conditions. Reducing the space between upper and lower side rails further improves safety. Though, not a common occurrence, the fact that it does happen has made leading medical companies like Stryker redesign their beds. The Stryker 3000 reduces the space between the side rails to 45 mm., and it also implements 5 mattress retainers to hold the mattress in place while moving (i.e, thus eliminating space between the bed and the rail).

Fall prevention is also important related to bed designs, especially for patients who are weak or have limited mobility. The Stryker Secure II accurately senses body position by tracking and balancing the patients’ center of gravity during egression. Egression is also made easier with side rails that are easily removed from the side and bottom of the bed.

Bariatric Beds

A significant issue with bariatric patients is that the size of the room, equipment, and facilities are too small to accommodate them. Hospitals often do not have the proper equipment to serve these patients, so beds may be “reinforced or lashed together as needed” (hfmmagazine). However, it is necessary to acknowledge that “high-quality bariatric beds address the challenges inherent in bariatric care (patient comfort and mobility and mitigating the risk of injury to caregivers and patients). Such beds have built-in scales and can be converted to chair position, a configuration to facilitate patient transfer” (hfmmagazine). Beds designed for bariatric patients are important in the recovery process and comfort of the patient and the safety of the patient and the caregiver.

Hill-Rom has used human factors approaches to design for two types of obese body shapes: apple and pear-shaped. Hill-Rom has discovered that oftentimes individuals with pear-shaped bodies prefer chairs without arms, while individuals with apple-shaped bodies have a preference for chair arms.

Beds range from accommodating a maximum patient weight of 460 lbs. (Hill-Rom: TotalCare Bariatric Bed), to a maximum patient weight of 1000 lbs. (Burke: Tri-Flex II). Bariatric beds offer a wider sleep surface than traditional hospital beds. Oftentimes the sleep surface is around 48” wide. All bariatric beds are fully electric in order to reduce the strain of the caregiver associated with adjusting the bed and patient together.

Home-Style Medical Beds
Several key design features desirable for home products include: simple and intuitive use, minimal maintenance, aesthetics, comfort and durability. Aesthetics are a major concern for home-style medical beds because they often are used in non-clinical settings (e.g., residential and nursing homes). Although there are a wide range of uses and models in this class of devices, accessibility and ease of use is especially important. Home-style medical beds often are used for pressure ulcer treatment or prevention, bariatric care, and respiratory care. With home-style medical beds, more control is given to patients than with medical beds used in hospital or clinical settings. Therefore accessibility of the control interface is especially important for home-style medical beds. It is also more likely that untrained caregivers will be using or helping patients use home-style medical beds, so designs should be simple and intuitive.

BaKare home-style medical beds feature an electronic handset control and adjustability which can provide relief from arthritis, rheumatism and common back pain.

Respiratory Beds

KCI and ProBed Medical Technologies are the leaders in medical beds for the purpose of treatment and prevention of respiratory problems. “A 40-degree or greater rotation on each side helps to treat and prevent respiratory complications associated with immobility” (KCI). This feature is powered so the caregiver is not strained while turning or repositioning patients on their sides. ProBed Medical Technologies beds have an automated rotation system that cycles patient positioning throughout the use of the bed so the patient is placed in different positions to relieve pressure. Users can program the rotation system to move patients to a specific pattern and position throughout a certain time period, and the angle through which the bed rotates can be either programmed or operated manually. Another manufacturer, Hill-Rom has found that a head elevation of greater than 30 degrees decreases the risk of Ventilator Associated Pneumonia (VAP) and the aspiration of gastric contents. Therefore they have implemented an alarm that signals the caregiver when the head of the bed is lower than 30 degrees.

Birthing Beds

Birthing beds can be used for sleep in the last stages of labor, but they are specifically designed for delivery. The Hill-Rom Affinity Three Birthing Bed has the latest features in delivery technologies of birthing beds. For the doctor, the seat section has a V-cut surface allowing maximum exposure to the mother’s perineum during labor and recovery for greater accessibility. For the caregiver, the foot section is removable in one motion and is the lightest on the market. The foot section also stands upright to keep the perineal edge off the floor. The foot supports with a lever release can be adjusted into calf supports. The bed is very mobile, with a battery that can control bed functions in emergency transport. For the patient, the seat section inflates for comfort. There is a photo sensor night-light at the foot exit area. The bed has a height adjustment from the floor to the mattress surface of 22 inches to 38 inches. to help mothers of all sizes to exit the bed. The bed adjusts to accommodate four different birthing positions increasing patient comfort and accessibility.

Recommendations for R&D

With regard to recommendations for this report, the Regular Bed section should be further divided to differentiate between ICU, therapy, and surgery hospital beds. The Product Table contains many of the main hospital bed manufacturers; however work must be done to contain all of their beds. Further work is needed to expand the Birthing Bed section of the table in this report.

Overall product recommendations for medical beds include:

It is also recommended that better caregiver training is implemented in order to reduce back injury. Hospitals should also be encouraged or given some kind of incentive to upgrade medical beds so that patients can benefit from the latest technologies. Focused improvement for beds specifically designed for particular medical needs (bariatric, respiratory, childbirth) should be emphasized in order to improve patient care and reduce the potential for caregiver injury.

Acknowledgment

This work is supported by the Rehabilitation Engineering Research Center on Accessible Medical Instrumentation, funded by the National Institute on Disability and Rehabilitation Research, U.S. Department of Education Grant #H133E020729. All opinions are those of the authors.

References

  1. Goldsmith, Connie. “Watch Your Back: Nursing Personnel can Prevent Workplace Injuries Before They Happen.” NurseWeek. January 8, 2001 http://www.nurseweek.com/news/features/01-01/back.asp
  2. "A Guide to Bed Safety: Bed Rails in Hospitals, Nursing Homes, and Home Health Care, the Facts." Food and Drug Administration website. March 2006. http://www.fda.gov/cdrh/beds/bedrail.pdf
  3. Harrell, James W. “Big Challenge: Designing for the Needs of Bariatric Patients.” Health Facilities Management. March 15, 2004. http://www.hfmmagazine.com/hfmmagazine/hospitalconnect/search/article.jsp?dcrpath=AHA/PubsNewsArticleGen/data/0403HFM_DEPT_Arch_and_Design&domain=HFMMAGAZINE
  4. Hedge, Alan. “Back Care for Nurses.” Spine Universe. http://www.spineuniverse.com/displayarticle.php/article1509.html
  5. Lemke, Melissa R. The evaluation of three alternative methods for understanding biomechanical aspects of medical device accessibility : mobile usability lab pre- and post-activity questionnaires, mobile usability lab video analysis with multimedia video task analysis, and medical equipment device-accessibility and universal design information tool. Marquette University, 2005.
  6. O’Shea & Associates [homepage]. http://www.nolift.com/