Truman CPR module – Case Study Design project

Torc Case Study

Design project – Truman CPR module


The control module is an integral component of the Trucorp Cardio Pulmonary Resuscitation (CPR) training unit. The brief for the function of this module was very strict. It needed to interact with the mannequin allowing real-time feedback to the user. The control module also required interaction with existing Automated External Defibrillator (AED) devices, using the same user inputs and similar audio and visual feedback.This component of the overall project gave the most scope for interpretation as the main unit was dictated by anatomy and we were to simulate but not copy existing devices.

Design project – Truman CPR module

Sketch Model:

After initial concepts were appraised it was decided that the most appropriate solution should be modelled up as a sketch model to give an idea of scale, aesthetic and usability. The majority of AED devices use membrane keypads, therefore, the concept chosen particularly exploited this type of user interface for realism. Some preliminary CAD was drawn to give dimensions and proportions and the model was fabricated to get feedback on the concept.

Alpha Prototype:

Working closely with an electronic engineer, we drew up a story board, mapped the inputs and outputs and produced a prototype printed circuit board that met these requirements.

At this stage it was too early in the process to get a membrane keyboard so we hand fabricated a housing that closely approximated the shape of the final design while holding the prototype components. This fully functioning model was used for alpha testing. The feedback from clinical experts allowed us to revise and refine the design and interactions with the software.

Beta Prototype:

Once the function was set, we again worked with the engineer to establish a board size and shape that worked with our design and we proceeded to 3D printed parts.

As we knew the volumes for this unit would allow it to be vacuum cast, we got high quality Stereolithography (SLA) models printed that could also be used as master patterns after the final testing was completed.

Feedback and Revisions:

In this instance, we only needed to make minor alterations to the SLA model. Adjusting boss heights to get the LCD to sit flush and adding features to hold the speaker in place more securely. The original mounting method interfered with the speaker output. These SLA models were then used to fabricate silicone tools and vacuum cast a batch of 5 for beta testing by the client.

There were some considerable software changes implemented at this point based on user feedback. These included translation of the audio to different languages and the addition of more scenarios to improve user training based on advanced training requirements. A further revision of the PCB was required to pass CE testing although none of these changes impacted on the physical shape of the unit.