Before my arrival, formative and summative tests were already part of Volta’s medical device procedures — but they were conducted in a “quick and dirty” fashion, without clear metrics or structured methodology.

As Senior Product Designer, I took the lead in formalizing and structuring these usability practices to make them measurable, repeatable, and clinically reliable.

Working closely with AI engineers, physicians, the product manager, and the regulatory team, I designed a testing protocol aligned with both medical device compliance and UX research standards.

Because testing in a real surgical environment was not possible, I created realistic interactive prototypes in Figma, faithfully replicating Volta’s interface behavior and visual dynamics.

This setup enabled controlled usability simulations, measuring how interface complexity and signal density impacted perception, attention, and coordination under time pressure.

We built a simulation protocol inspired by Measuring the User Experience (Tullis & Halbert), defining clear performance indicators such as:

• Detection errors (missed visual signals)
• Announcement errors (verbal communication issues between physician and mapping engineer)
• Input errors (incorrect tagging in the mapping software)

Each simulation progressively increased the number of signal channels — from 10 to 24 — to evaluate the tipping point where the interface would become cognitively overwhelming.

Over 15 simulation sessions involving 18 participants (physicians, mapping engineers, and clinical specialists), we captured both quantitative performance data and qualitative feedback on visual comfort and workload.

Sessions were recorded, coded, and analyzed to identify cognitive breakdowns and determine an optimal usability threshold.

The data revealed a clear limit: beyond 16 channels, both signal detection accuracy and communication between the physician and the engineer began to deteriorate.
Stress indicators and confusion increased sharply past that threshold, confirming that more data did not mean better decision-making.

Physicians unanimously favored the 16-channel configuration, which provided sufficient signal coverage without compromising focus or workflow continuity.

“With too many channels, we lose focus and forget what was already called out,” one physician said during the tests.

This insight led to a decisive design recommendation: limit the interface display to 16 channels for clinical use. That configuration is now part of the commercial product deployed in hospitals, praised by physicians for maintaining both precision and clarity.

Beyond the test results, the project became a turning point for Volta’s design maturity.

Starting from a blank slate, I introduced Figma as a design and prototyping tool, built a component library to quickly replicate test scenarios, and trained engineers and PMs in usability testing methods.

I also helped the regulatory team integrate this new process into Volta’s documentation framework, bridging user experience validation and medical compliance.

Despite limited resources and physician availability, this approach de-risked the interface before release and established a shared understanding of design’s value in product reliability.