Project “OptoBrain”

Developing a user interface

The project “OptoBrain” was initiated by the Swiss company Luciole Medical AG ( former start-up company called NeMo Devices), funded by the Eureka Initiative. The goal of the project was to develop a system for measuring cerebral vital signs, such as oxygen saturation in brain tissue, cerebral blood volume and blood flow.

In the following, we use this project to visualize how an interface may be developed.

The OptoBrain system is composed of several hardware components as well as sensors, which are necessary for measuring and processing the data. The values are analyzed and displayed on a PC suitable for medical applications with a user interface developed by the Use-Lab design team.

Here you can find a video about the project:

Requirements analysis

The central challenge at the beginning of the project was the requirement for a resolution that was as flexible as possible, since the software was to be used in a wide variety of environments and scenarios. After an internal analysis of the existing software from earlier stages of development, we decided to rework and redesign the user interface from scratch.

Even before the initial design phase, the design team conducted an extensive field analysis of the environment and workflow in which patients with traumatic brain injury are treated in an intensive care unit. In addition, we gathered information from users on the strengths and weaknesses of existing systems. Based on this analysis, initial ideas, notes, and sketches were created, which were then incorporated into the later design.

Information architecture

At the beginning of the first design phase, the information architecture for the system was created in an iterative process. The result of the process was a constantly growing mind map that extensively outlined the later structure.

Design concept

The previous version of the software had provided an overview of the required functions. However, since the focus here was on the new development, we decided to completely rebuild the layout. Backwards compatibility played a major role, along with the handling of memory formats, in order to meet the expectations of existing customers. Any serious change in the layout or the operating logic carried the risk of being met with rejection by the established user base, and it also had to be designed in such a way that it would allow future extensions or changes.

In the course of the new development, we developed various layouts and examined them with regards to conformity to requirements and user-friendliness.

Formative Usability Evaluation I

The first formative usability evaluation was conducted as a focus group discussion with future users. After the sketched designs had been presented and explained, participants’ feedback regarding their expectations was gathered and evaluated. The focus group also served to identify the preferred layout idea.

One of the insights gained was that most users today look for a “home” and “back” icon and assume they can swipe on a touchscreen because they are so used to smartphones and tablets.

Adaptation of the design concept

Based on the results of the focus group, many of the initial ideas were discarded. From a project management point of view, this is a goal-oriented process and thus an enormous step forward. Sketches and interaction flows were revised and adapted on the basis of these results.

Detailed design

In the course of the following design step, the drafts were continuously developed and adapted. Up to this point, the representations were made exclusively as hand sketches.

We tested various design options using an example screen layout and compared them with regards to their appearance.

To derive a style guide, various aspects of the appearance of the screen were systematically added and removed until the essence crystallized. This was then applied to all screen layouts.

Interactive simulation

We developed an interactive model for the objective evaluation of a user interface. Being able to “play” with the product, allowed previously hidden deficits to be revealed. By creating an interactive simulation, the individual screen states were no longer viewed in isolation, but rather interacted with each other and simulated concrete process flows.

The OptoBrain project offered the possibility to create simple interaction simulations to observe the interaction flow. As a basis for the second evaluation phase, more complex scenarios, such as sensor assignment, were additionally represented with a more detailed simulation.

Formative Usability Evaluation II

The second evaluation phase was about the “finishing touches” before implementation or usability validation. This is often the last opportunity to optimize the design during the process without having a significant impact on the budgeting or schedule.

In one-on-one interviews, potential end users were asked to complete various use scenarios with the simulated interface in order to identify potential improvements.

Use difficulties during the execution of the tasks were an indication for improvement potential. In these cases, it is always important to talk to the participant to find out exactly where the difficulties lay and what ideas for improvement they might have.


Before implementing the final design, an exact specification of the layout and a library of all image elements used in the interface must be created. In the case of the OptoBrain interface, this was done by laying a uniform grid over the screens, which could be used to read off the size and position of the individual elements.


In addition to the interface design, the Use-Lab design team developed the marketing concept for the OptoBrain system. This included the advertising presence including product presentation, trade fair stand, numerous illustrations and 3D renderings for the design of various print media, as well as the graphic design of the packaging and the creation of the user manuals.

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