Design of the advanced commode-shower chair for spinal cord-injured individuals.

The purpose of this development project was to design a new commode-shower chair that can be safely used by individuals with spinal cord injuries (SCI) and their caregivers. The need for this new design was consumer-driven. Patients and caregivers identified the following fatal flaws in the commode-shower chairs used in Spinal Cord Injury (SCI) centers: 1) risk for patient falls during transfers, propelling, and while leaning over for showering; 2) risk for pressure ulcers due to inadequate padding and seat positioning for lengthy bowel care regimes; 3) inadequate caregiver access to the perianal area of the patient to perform bowel care procedures; and, 4) wheel-related inability to properly position the chair directly over the toilet. The new, self-propelled chair addresses each of these concerns. Lockable, swing-away, pivoting armrests and improved, lever-activated brakes were designed to facilitate safe transfers. An innovative foot-lift was invented to facilitate washing of feet. Larger handrims were designed to aid in propulsion in wet environments. To prevent pressure ulcers, a chair frame and padding combination was designed to facilitate a seating position that optimally distributes body weight to prevent the development of pressure ulcers in the sacral and ischial areas. To address the common risk of heel ulcers, footrests, featuring edgeless, rounded heel cups, were designed. A new tubular chair frame, a new seat and smaller wheels were designed to enhance caregiver access and ensure proper chair positioning over the toilet. Following its successful clinical evaluation at the Milwaukee and Tampa VA Medical SCI Centers, the Advanced commode-shower chair is being patented by the Department of Veterans Affairs (VA). The VA has partnered with Everest & Jennings, to make this chair available commercially.

Promoting safe use of equipment for neurogenic bowel management.

Nurses have a responsibility to monitor patient safety related to the use of equipment. Existing bowel care/shower chairs used by persons with neurogenic bowel can pose serious safety risks for patients. Twenty-four percent of persons with spinal cord dysfunction reported development of pressure ulcers and cuts from the seats, and 35% reported a history of falls from bowel care/shower chairs. Of those who reported injuries due to falls, more than 23% reported that they were hospitalized from 1 month to 4 years due to injuries from the fall. Many of the pressure ulcers and falls that occur from the use of bowel care equipment can be prevented. A combination of design flaws and user error are responsible for these safety risks. Design flaws in existing equipment include seat design, seat configuration, footrests, armrests, hand rims that are difficult to propel when wet, unreliable brakes, and chair frame instability. User error that contributes to pressure ulcers relates to poor posture in the chair. User error that contributes to patient falls relates to leaning over to wash the feet and lack of maintenance of air pressure in the tires, which affects the brakes. A series of research and development projects enabled the authors to design a new bowel care/shower chair that incorporates many new features and inventions to enhance patient safety.

Patient evaluation of prone carts used in spinal cord injury.

Prone carts are used for mobility by individuals with spinal cord injury who cannot use a wheelchair due to the risk of aggravating existing pressure ulcers. A prone cart is a flat/horizontal cart with a fixed height, propelled by the user while laying in a prone position. Patients reported that prolonged use of a prone cart resulted in chronic neck, shoulder and back pain. Additionally the existing prone carts lack user accessible angle adjustability, chest support area, as well as a storage, eating or working area. An interdisciplinary research team collaborated to address these concerns. Three prone carts were evaluated: E&J, Gendron, and a newly developed prototype, MIAD/PVA. Questionnaires were administered to caregivers and patients regarding usage and effectiveness of the prone carts as well as the features of an ideal cart. This data led to the design and refinement of a prototype prone cart which was tested on 20 patients and 19 caregivers at the SCI Centers of the Milwaukee and Tampa VAMC's from 1994-1995. The new prone cart enables the user to lie at an angle rather than laying flat. This position has been found to relieve back and neck pressure. With an hydraulic system, the the user can adjust both the front and rear angles of the cart to achieve desired comfort. In addition, a front deck provides an eating and working area. This study resulted in research-based information and criteria for the design of new prone carts. Findings of this pilot study will be incorporated in a development merit review proposal to the VA Rehabilitation Research & Development service for the design of a new manual and motorized prone cart. The researchers are collaborating with Ortho-Kinetics Inc. to promote ease in manufacturing.

Time-of-day variations in oculomotor function: I. Tonic accommodation and tonic vergence.

Time-of-day variations were studied both in tonic accommodation and in tonic vergence. Thirty-six male volunteers were measured once in the morning and at one other time on the same day. The mean baseline value of tonic accommodation was 2.02 D. Time-of-day variations were found, with a late evening measure being +0.6 D greater than the morning value. No independent time-of-day fluctuations were found in tonic vergence. Post-hoc analysis, however, showed that tonic vergence tended to shift in the same direction as an individual's tonic accommodation during the afternoon. During the evening, tonic vergences tended to shift oppositely to tonic accommodation.

Time-of-day variations in oculomotor function: II. Steady-state accommodation to square-wave gratings.

Time-of-day variations in both tonic accommodation and steady-state accommodation to a grating were assessed for 16 observers who were tested once in the morning and again 12 hours later. The mean night-time tonic accommodation was +0.5 D greater than the morning value. Square-wave gratings of 4.2 and 8.4 c/deg were presented to the observers at distances of 0, 1.07, 2.13, 3.2 D. Over-accommodation to far targets and under-accommodation to near targets occurred for both gratings. All values of steady-state accommodation were somewhat greater in the evening. Large individual differences were noted.

Perceived loudness and visually-determined auditory distance.

Three experiments were conducted to determine whether variations in the perceived distance to a test sound could influence its loudness in the absence of physical changes in sound-level. The phenomenon of visual capture provided the means for manipulating apparent distance. A 'dummy' loudspeaker was used to vary the apparent source location of a short noise stimulus while the true source of this sound remained fixed (and hidden) with respect to the observer. Sound-levels from 40 to 75 dB(A) were presented to independent groups of observers in either anechoic or semi-reverberant acoustical environments. In general, reported loudness increased with perceived distance. This finding has implications for conceptualizing the phenomenon of loudness constancy.

Stability of measures of the dark focus of accomodation.

Without visual stimulation, the eye tends to assume an individually-determined intermediate state of accommodation (the "dark focus"). The present study examined the stability of these individual dark focus values over time. Two sets of measurements were obtained with a laser-Badal optometer for each of 39 college-age subjects. For 19 subjects the second test occurred during the same experimental session as the first; for 20 subjects the retest was conducted in a separate session 1 week later. Eye dominance was determined by a pointing task. High correlations between test-retest values were found for both immediate and delayed retest. The average change between the tests was less than +/- 0.3 diopter, even when the retest was a week later. These results indicate a definite stability in individual dark focus values. Eye dominance and subject's sex were both irrelevant.