Interactive cognitive artifacts for enhancing situation awareness of incident commanders in mass casualty incidents

Mass casualty incidents

Train and airplane accidents or terrorist attacks often result in publicly recognized MCIs. Nevertheless, even minor events can generate “more patients at one time than locally available resources can manage using routine procedures” [8]. Contributing factors can be time of occurrence (e.g. at night), location of accident (e.g. freeway, poorly accessible areas), weather conditions (e.g. heavy rain, snow, storm), and utilization of responsible EMS (e.g. while being in charge of other events at the same time).

Managing MCIs efficiently will only be possible, if operations are co-ordinated and EMS members led by superiors. Courses of action need be coordinated and a spatial order has to be established (tactics). Triage, i.e. efficiently determining severities of injuries and prioritizing treatments, is regarded to be the most important task following basic life support actions [10]. It implies an order in which casualties are transferred from triage to transport. The process should be supervised by the chief emergency physician and supported by the ambulance incident officer. Furthermore, they are responsible for organizing and running specifics areas of operation for triage, treatment and transport. A specific flow of information between the incident commanders and these operation areas is crucial for performing actions in classified order. They have to be documented as complete and comprehensible as possible. Physicians in charge at hospitals receiving victims of MCIs have to rely on these records. Furthermore, EMS employees who are still waiting for being involved should be informed about the following mission.

Treatment, i.e. medical care of ill or injured people, and taking care, i.e. crisis intervention and emergency pastoral care, need to be adapted to the circumstances. Standards and procedures of individual care would be too time-consuming or resource-intensive. Finally, casualties need to be taken to clinical environments for further treatments (transport).

Situation awareness in MCIs

Tools and aids for record keeping and information management should support incident commanders’ work and decrease their workload while accomplishing several unusual tasks in parallel and under time pressure.

Cognitive artifacts in MCIs

Cognitive artifacts can be defined as “artificial devices that maintain, display, or operate upon information in order to and suitable serve a representational function and that affect human cognitive performance” [16]. On different levels of abstraction they represent entities and relationships which are of peculiar interest in a specific domain [17]. With regard to MCIs, these are patients and their medical conditions as well as available medical resources (e.g. vehicles, physicians, utilization of hospitals). Some of them are locally available; others have to be requested from a distance.

Cognitive artifacts are meant to support and ease human problem solving as well as accelerate and improve task completion. However, from a personal view, introducing or modifying cognitive artifacts changes the way how people can accomplish tasks and how cooperation will be conducted [16]. Incident commanders have been skilled in different topics (e.g. emergency medicine, command and control), but they are different from operators of other complex socio-technical systems (e.g. aviation) in several respects. First of all, they do not perform supervisory control on a daily basis. Crews for regular missions consist of 2–3 persons and work together as well-matched teams side by side. Secondly, although applying sophisticated medical technologies regularly, they are not used to interactive and multimodal human-machine interfaces in everyday professional life.

Cognitive artifacts represent “a meeting point […] between an ‘inner’ environment, the substance and organization of the artifact itself, and an ‘outer’ environment, the surroundings in which it operates” [18]. In terms of EMS employees’ working conditions, the latter can hardly be planned ahead because MCIs can occur anywhere and anytime. In spite of that, they are rare events for a specific incident commander (cf. [19] for an exemplary analysis of a German district). Therefore, cognitive artifacts in this safety-and time-critical domain have to be suitable for the task, self-descriptive and conform to user expectations. Learning and adaption phases have to be avoided respectively minimized. Otherwise, such artifacts might be a danger to life and health or would not be used at all.

Cognitive artifacts for enhancing SA in MCIs

Currently, incident commanders mainly rely on paper-based cognitive artifacts [20, 21]. Forms and tables, maps and charts, and private notes can be distinguished and are discussed below. Because basic aspects like triage categories or crucial topics for incident commanders (e.g. number of patients still to treat), the selected examples of German EMS are comparable to the ones used in other countries [20–22]–although there is not even a nation-wide standard.

Forms and tables

Dedicated documentation and information systems have been developed in preparation for MCIs. They consist of various forms, which are suitable for certain areas or phases of a mission. While some of them are commercially available, others have been introduced by EMS on their own. Figure 2 shows a table with columns for patients’ identifiers, names, triage categories and diagnoses. Most entries were added by handwriting. Identifiers were taken of triage tags and affixed to the form. As Fig. 2 depicts, there is a mismatch between row and tag sizes. It complicates clear assignments and readability. Such problems related to layout, color contrast and overall design of artifacts are no exception.

Typically there will be templates for

• summarizing time and result of each patient’s triage at the triage area;

• documenting actions at the treatment area(s);

• registering transport decisions at the staging area (e.g. vehicle, patient, destination, departure time);

• recording hospital assignments in order to ensure balanced distribution;

• organizing the assembly area (e.g. arrival and departure);

• enabling quality management by consolidating data from different sources.

In addition to such mainly textual and tabular representations, graphical notations are established as well.

Charts and maps

For visualizing organizational structures or spatial relations, incident commanders make use of different charts and maps. While some of them can be carried around (Fig. 3), others are fixed at a command vehicle. Magnets or tactical signs can be applied to some of them for showing recent developments in the field. Several maps are necessary for different resolutions (e.g. vicinity, proximity, buildings) and aspects (e.g. topography, infrastructure).

Apart from using templates and published materials, many incident commanders record certain data individually.

Private notes

Some of these sheets of paper are prepared in advance, e.g. by dividing sections or listing keywords. Others are initially blank and structured on the fly (Fig. 4). Most of them are used for short-term memorization only. Sometimes they are left behind after just a few minutes of usage without referring to the notes again during or after the operation.

General remarks on usability

Developing interactive cognitive artifacts for the context of pre-hospital medical care is a challenge for various reasons. Interface and interaction should be designed iteratively and by user participation. However, short-term scheduling is complicated by work schedules and staff requirements.

Field studies and test runs can hardly be projected. Workshops, interviews and expert reviews often take place in conference facilities or office rooms. Such favorable conditions differ completely from the real context of use. Thus, natural environments, interruptions and other performance disturbing factors that characterize MCIs have to be considered specifically and carefully. What seems like an appropriate approach in a relaxed training situation might be a hardly manageable case of information overload in the field. Furthermore, computer-based tools and systems are an additional medium of communication and channel of information. They have to be aligned with established workflows and organizational structures which depend on thorough exchange of radio messages.

Practice in efficient and safe handling as well as operating interactive cognitive artifacts cannot be ensured by exercises or training courses alone. It can only be derived from intense and regular application. Because MCIs are rare events for single EMS employees, this requirement can only be met, if interactive systems will be used in daily routine and not just during MCIs. A rugged tablet PC (Fig. 6) can be considered an appropriate hardware solution for a consistent user interface designed for regular and extraordinary missions. We have basically confirmed this in formative and summative evaluations based on a prototypical application [4, 5].

Because of possible difficulties arising from wearing gloves, touching accidentally or working with dirty hands, pen-based interaction should be supported by the system. Losing the pen might be an additional risk but it can be minimized by fastening it with a tear-resistant but flexible ribbon. Other input methods which are supported by state-of-the-art and off-the-shelf tablet PCs, e.g. speech or gestures, have to be judged critically. One the one hand, speech input usually demands high working memory resources of users and recognition rates could drastically decrease in noisy environments like MCI settings. On the other hand, gestures have to be remembered and performed correctly. This might be challenging with respect to weather or physical conditions.

Among other aspects, consistency can be ensured or improved by using well-known and appropriate layouts, data input widgets, visualizations, feedback mechanisms, error messages, symbols and colors. Although striving for it, certain screen layouts and interaction elements, which are important to MCI management, will not be used by incident commanders in their daily duty as regular emergency physicians or paramedics. One example is the distribution of triage categories shown in Fig. 6. Especially while dealing with well-known design issues for these parts, well-established design principles (e.g. [24]) should be considered. These best practices need to be applied to the specific context of MCIs [25]. As they represent essential entities and relationships, currently used cognitive artifacts might be an appropriate starting point for this process.

In safety-and time-critical domains with highly skilled personnel, it seems advisable to build upon practical experiences. Furthermore, questions of automation, adaption, and individualization arise with respect to division of tasks between human and machine. User interfaces and interaction methods have to be designed with respect to hardware capabilities (e.g. screen size, resolution, input and output modalities) and context.

Challenges and approaches to ergonomic design

As mentioned before, incident commanders currently take private notes and work with various paper-based documents in order to enhance their SA. Some of them are stationary and others have to be delivered manually. They can be arranged, sorted, or marked by the user to a limited extent. Computer-based tools allow data access and exchange near real-time and from remote but offer only limited screen space. Feedback about incoming data must be given explicitly.

Charts and maps

The number of patients in specific triage category is one of the most important chunks of information for incident commanders. In addition to tabular or textual visualizations, bar charts can be an appropriate design solution. During our workshops we presented four drafts differing in the number of categories and labeling (Fig. 7) to 36 EMS employees. We asked for their favorite or a self-created version. While 2 responses were ambiguous, 34 could be evaluated. The 3 most preferred versions got 9, 6 and 5 votes, respectively. 5 participants created their own solution. Allowing for minor modifications, e.g. position of labels, one version got 14 votes. The drafts were subject of controversial discussion. They enabled us to better match our conceptual model with their mental model beyond the use cases associated with the actual chart.

Using location-based services by tracking casualties, EMS employees or vehicles and visualizing them on maps looks promising but raises issues of reliability. Both tracking inaccuracies (e.g. in buildings, under bridges) and loss or removal of locatable items (e.g. by casualties in a state of shock) could result in inaccurate data. Such data would be worse than none at all. More or less stationary information (e.g. territorial allocation of operation areas) can be represented more reliable (Fig. 8).

Data exchange with geographic information systems in emergency control rooms or command vehicles might be necessary. Moreover, some incident commanders and EMS managers expressed reservations about modifying situation maps by multiple actors. They were strongly in favor of a read-only mode for co-workers in the field.