The software had to be intuitive, requiring minimal training so surgeons could access critical information without losing focus.
Quadsense
Skills
UI/UX Design
Tools
Figma
Adobe Illustrator
Adobe Photoshop
Adobe After Effects
Adobe Premiere
Background
I led the UI/UX design for Quadsense, a surgical tool developed with Eventum Orthopaedics for total knee replacement procedures. Working closely with surgeons and engineers, I designed an interface that delivers precise, real-time data in an intuitive, easy-to-read format, optimised for the high-pressure environment of an operating theatre.
About
Over 2 million total knee replacements are performed each year, yet up to 20% of patients remain dissatisfied – often due to poor patella (kneecap) tracking and alignment. Even small misplacements can cause pain, reduced mobility, and costly revision surgeries, adding to a $6.5B global burden.
Quadsense, developed with Eventum Orthopaedics, addresses this by giving surgeons real-time feedback on patella forces before and after implantation. With clear comparative data, it helps achieve accurate alignment and better patient outcomes.
Requirements
Developing the software required a deep understanding of surgeon needs, gathered through discussions with Eventum, focus groups, interviews, and procedure research. From this, we defined the core criteria the solution had to meet.
01
Ease of use
Surgeons are accustomed to established workflows and can be hesitant to integrate unfamiliar tools mid-procedure. Any solution needed to be surgeon-led, and suit their needs.
02
Reduced Cognitive Load
Theatre conditions are high-stakes and fast-paced, leaving little room for distraction or delays. The workflow needed to be easy-to-use, intuitive and reduce cognitive load.
03
Efficiency
Total knee replacement procedures are time-sensitive, requiring efficiency and precision throughout. The solution needed to be efficient, with quick paths through the workflow.
04
Shallow Learning curve
Method
Having identified key requirements, we adopted an agile design approach through rapid ‘test-learn-refine’ cycles. Embracing short feedback loops allowed us to quickly validate concepts with users and ensured strategic, data-driven design decisions.
I was deeply involved in every stage of the process—from conceptualising and refining ideas to leading and synthesising user testing.
Workflow
In the high-pressure operating theatre environment, the interface had to focus only on essential tasks. By mapping the procedure step by step, we defined the core user journey – from setup and baseline reading to comparison, analysis, and confirmation.
Next, I translated this structure into a written UX “script”, outlining each screen and its content in simple terms. This made the flow easy to review and revise collaboratively, even for non-design team members. The result was a well-rounded, team-validated script that laid the foundation for the product’s user experience.
01
Start & Setup
The surgeon selects the workflow (Streamlined or Advanced) and confirms left or right knee.
02
Enter Patient Data
In Advanced mode, patella thickness and implant details are entered, tailoring the workflow to the patient.
03
Baseline Recording
With the sensor attached, the surgeon records flexion–extension cycles. The system plots forces across the patella to create a baseline graph.
04
Comparison Reading
After trial implants are inserted, the surgeon repeats the process. A second graph appears, directly comparable to baseline.
05
Data Analysis
The software highlights differences in patella forces. Surgeons can toggle between load traces to spot imbalances.
06
Additional Readings
Alternative shims can be tested. Each new reading is logged with its parameters for easy comparison.
07
Decision Support
Advanced mode calculates resection depth/angle if needed and flags risks if the patella becomes too thin.
08
Confirm & Finish
The surgeon confirms implant size and resection choice, ending the workflow and proceeding with implantation.
Wireframe
Through wireframing and early prototyping, we refined the interface flow, reduced cognitive load, and ensured that the software aligned with real theatre conditions before committing to the build.
Brand Language
Beyond functionality, the software needed to reflect Eventum Orthopaedics’ brand values of trust, precision, and innovation. I worked with the team to define a consistent design language – typography, colours, and iconography — that improved legibility aligning with the brand. The result was a professional, intuitive interface that reinforced usability in surgery and strengthened Eventum’s wider medtech identity.
Prototype
To validate the design, I iterated through interactive prototypes in Adobe XD. This allowed us to simulate the full surgical workflow, test navigation patterns, and gather direct feedback from surgeons before finalising and releasing the product for trials.
Test the prototype here →
Outcome
Following the development of the Quadsense tool, Eventum Orthopaedics secured £3.8 million in funding from NPIF II (via Mercia Equity Finance), along with EIS funds and private investors, bringing their total raised to £7 million. The product has received glowing reviews from Orthopaedic surgeons and continues to see increased uptake year-on-year for TKR surgeries.
Quadsense has already gained regulatory approvals in the UK and US and has been used in over 300 surgeries, while distributors have been appointed across key international markets.
”“Quadsense guides me in the surgery where previously I didn’t have a guide.”
Professor David Barrett BSc MB BS FRCS
