Putting Usability at the Heart of Monitor Design

An expert usability review, evaluation against usability best practice and user testing helped LiDCO to produce a successful new heart monitor.

LiDCO researches, develops, manufactures and sells innovative medical devices.  These devices aim to transform complex, raw physiological data about a patient into useful information for medical staff, clearly displayed at the point of care.

 Timely response to this information has been shown to improve the recovery time of patients and significantly reduce complications following surgery.

System Concepts has worked with LiDCO to understand and improve the usability of their latest cardiac output monitor, LiDCOplus.  

The issues

Medical systems often fail to deliver the expected benefits because they:

• are not suited to the real users and their approach
• fail to take account of users’ skills and experiences
• are not tested in realistic conditions and often are not tested for usability at all
• lack standardisation, often because there is no set standard
• are not implemented with sufficient training and support.

Specifically, LiDCO identified a number of issues with standard medical monitoring equipment, which is often:

• not PC based and therefore not flexible
• focused on raw data acquisition and display
• poor at showing the relationships between the different data sets
• complicated to set up or change the user interface.

What we did

LiDCOplus is a cardiac output monitor used by nurses to monitor and optimise oxygen delivery in intensive care units.  LiDCO designed a monitor which:

• was easy to set up and interpret
• displayed information in natural groupings
• told a story rather than just displaying raw data.

System Concepts reviewed and tested both the interface and the instructions to ensure the product could be used efficiently and effectively. 

We first observed nurses using the monitor as part of their normal duties in an intensive care unit to understand how their use of the monitor was affected by their surroundings and work practices.  Through systematic observations and interviews with the nurses, we were able to find out:

• how often the monitors were actually used
• what monitor functions were being used
• how these differed depending upon the nurses’ experience
• how the set up of the monitor with both the patient and other equipment affected usage. 

We identified some initial usability issues.  The nurses were:

• not familiar with the innovative features and icons of the interface design
• not confident using the system
• struggling to remember the operating procedures since the majority of users operated the system once or twice a month

Once we fully understood this ‘context of use’, we evaluated the user interface and instructions against usability best practice and recommended improvements to both the interface and the procedures.

Following our recommendations, LiDCO developed a new interface design which we tested against the original design with novice users in a simulated working environment.  Although we still found some usability issues, there were definite improvements:

• 80% of participants completed all tasks successfully
• the new interface design was perceived as easier to use
• the “help me” feature was seen as a useful and helpful addition
• the data from the new interface design was perceived as safer and more accurate
• none of the participants required training.

What does the client think?

Eric Mills, LiDCO’s product development manager said

We knew that identifying what the user wanted to know, keeping it simple and designing the tool for the task was the key to a successful product.  System Concepts’ expertise in interface design and user testing helped us to put this into practice.

We found their approach innovative and flexible, and their recommendations clear and practical.  They built up good relationships with our design team and made a significant contribution to the success of the product.

Last updated: October, 2009

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