Ensuring bed space is right first time

The bed space is the largest repeating design unit in hospitals; and is found in a range of configurations, from multi-bed bays to single rooms. This space presents a complex design challenge due to the different people who will occupy the space (patients, clinicians, support staff, visitors etc.) and the wide range of task activities.1

The recommended bed space width has gradually increased over the last 50 years and there are now five international publications recommending a minimum of 3.6 m bed space width for both a cubicle and a room.2-6 The Nuffield Provincial Hospitals Trust’s studies of 1955 were the only historical documents to provide empirical research to support the recommendations.7 It used workstudy techniques and simple cinematographic data collection to measure the space required for nursing activities using floor-marked grid lines at 12 inch intervals. The activities included bed making, pressure care, manual handling (bed-wheelchair and bedtrolley), giving an intravenous infusion, arranging an oxygen tent over the bed, and taking an X-ray from the front and side. To address the research gap of empirical evidence to support healthcare facility design a protocol was developed for the development, revision and testing of ergonomic envelopes.8

Development of task envelopes

This article will describe the development of task envelopes (TEs) for intensive care bed spaces,9-10 wards and bariatric FSEs (functional space experiments). TEs present a complex spatial representation to incorporate multiple activities, participants and interfaces. The workspace ergonomic envelope was previously defined as dynamic reach activities in 3-dimensions (kinetosphere).11 The advantage of using a TE rather than a traditional ergonomic drawing is increased flexibility. A TE is not the room dimension, but a system that informs the design process by providing information about the non-reducible spatial requirements for functional activities rather than prescribing specific dimensions and layouts.

It is anticipated that TEs will facilitate the creative process in design, encourage innovation, and offer a speedy response to changes in working practices, equipment and technology. We recommend that the following 5-step protocol should be used for future development, revision and testing of TEs:

Step 1: Define an example to test or build to produce a layout from “real life”. This could include current recommendations/guidance or dimensions from existing facilities.

Step 2: Observe task activities using hierarchical task analysis (HTA) and link analysis (LA) to develop a test scenario based on the frequency and criticality of activities. The observations were carried out for frequently conducted and safety critical nursing tasks. HTA was used for the data analysis to identify individual variance and generic task components to develop the simulation scenarios for the FSEs. HTA is a technique used to analyse data by breaking a task down into subtasks until a stopping point is reached when the task cannot be further broken down.12 Figure 1 gives an example of transferring a patient from one bed to another.

The LA method relies on observations or a walk-through to establish links between components in the system, and then uses spatial diagrams to analyse movements between these components.12 It was used to look at spatial relationships within a defined area, in the collection and analysis of the observational data, and in the analysis of the FSEs to determine the optimal layout and improve design. For each task a link analysis was completed, as shown in Figure 2. The most frequently observed task in ICU was washing a patient and changing the bed sheets. The bed head was the least occupied area during the task, and the area most occupied was the patient’s right side, where the bin and the nurse trolley were located.

Step 3: Conduct FSEs within the test scenario to determine the average spatial requirements for the TE. FSEs were developed to test the space required for the tasks identified in the field observations. The simulations were designed to test the different layouts and dimensions using patient scenarios (see Fig. 3). Bed space mock-ups were built using different coloured floor tape at 10-20 cm intervals for measurement. Moveable walls simulated the nurses’ experience of the physical space and could be “pushed out” if more space was needed during the task.

Three tasks were chosen:

Four-way directional videotaping was used to record the participant’s movements between equipment, furniture and the simulation mannequin (patient) for further analysis. The multidirectional video data was analysed frame-by-frame to plot the movement of each nurse individually and then overlaid with that of their colleagues (Fig. 4).

Step 4: Take additional information into account, for example storage, family space and circulation, regulations, standards etc. to fit the TE into a specified (generic) room dimension. This step is usually carried out by the building designer in consultation with the ergonomics advisor.

Step 5: Use steps 1-4 to test spatial requirements following changes in working practices and the introduction of new equipment/technology.

Results

FSEs were carried out for: