Kardion

Kardion MCS Controller as a regulated medical-device interface with FDA approval

Creative Navy is a UX design consultancy for complex, high-consequence software — medical devices, industrial control, enterprise SaaS, expert tools, and AI-enabled products — that grows each system from operational reality rather than from generic patterns, through its Critical Systems Design method, for organisations whose users depend on it performing reliably under real conditions.

Kardion GmbH engaged Creative Navy on the Kardion MCS Controller, the external control unit for a minimally invasive mechanical circulatory support device inserted percutaneously into the left ventricle of the heart. The controller manages blood flow delivered by the implanted pump, displays device status and sensor data, and handles alarms. The controller is a regulated medical device requiring FDA approval and designed to the IEC 62366-1 usability engineering standard.

The Kardion MCS Controller supports two clinical scenarios through one controller. The Cory P4 pump supports patients during high-risk percutaneous coronary intervention procedures for short-term use, up to 6 hours and up to 4 l/min. The Cory LV6 pump supports patients in cardiogenic shock for longer-term recovery, up to 14 days and up to 6 l/min, with additional pressure and flow sensors.

The physical controller has a 12.1-inch touchscreen with 1280×800px resolution, is pole-mounted, weighs 3.5kg, and includes a rotary knob on the right side for flow adjustment. The controller also has a physical alarm LED, a mute button, and battery-backed operation for patient transport. The controller sits in the non-sterile field while the implanted device is in the sterile field.

Primary clinical users had different information needs and screen positions

The Kardion MCS Controller had to serve scrub nurses, perfusionists, and ICU nurses through one interface. Scrub nurses and perfusionists use the controller in the cath lab or operating room during procedures. ICU nurses use the controller during longer-term cardiogenic shock support.

Creative Navy's design work treated the user groups as genuinely different operating roles rather than as generic medical-device users. Scrub nurses and perfusionists monitored motor current and device positioning signals, particularly during insertion. ICU nurses focused on flow rate, arterial blood pressure, and run time. Secondary users included ICU physicians, authorised hospital staff, and transport staff.

The same controller also had to work across different viewing distances. During procedures, surgeons stand approximately 3 metres from the controller and need to read the critical flow value without moving or diverting sustained attention from the patient. Nurses work close to the controller and need access to more detailed monitoring information.

Emergo by UL formative study as the starting evidence base

Creative Navy began from an independent formative usability study commissioned by Kardion from Emergo by UL, Human Factors Research & Design. The study was conducted in Concord, MA, involved 7 participants, and tested two physical design prototypes and a GUI prototype across 8 clinical use scenarios. The participant group included 2 scrub nurses, 2 perfusionists, and 3 ICU nurses. All participants had recent Impella controller experience, and 6 of 7 participants had used an Impella controller within the previous 6 months.

The Emergo by UL study was governed by IEC 62366-1 and documented under Kardion's quality management system. Creative Navy used this independent formative study as the starting evidence base rather than beginning research from scratch.

The Emergo by UL study established several GUI-relevant findings. Users read the screen from top-left, clockwise, and alarm placement in the top-left corner was strongly preferred and validated. Most users focused on true flow before set flow. Min/max flow readings were consistently misunderstood, with users inferring that they were device-set safety limits rather than readings of actual device output variation. Colour differentiation between flow and pressure data was positively received, and the screen was read well from multiple angles and distances.

The Emergo by UL study also identified gaps. A step-by-step setup guide similar to Impella's was expected and missing. Most participants considered the 3-minute startup time long. The study did not surface the actual choreography of clinical use: the spatial and procedural relationship between surgeon, nurse, controller, and patient; the thought process clinicians follow when making flow decisions; and which information elements are relied on at specific workflow moments.

Creative Navy mental model sessions established clinical logic for information hierarchy

Creative Navy ran additional user sessions with cardiologists and nurses after the Emergo by UL study. These sessions focused on domain learning: understanding clinical practice, the choreography of nurse and surgeon during a procedure, the medical decision-making process around flow adjustments, and the situations in which each screen data element becomes clinically relevant.

Before Creative Navy's mental model sessions, the rationale for showing some information was that it could be shown. The sessions established a more specific clinical logic: which information was needed, at which moment, and for what reason. This informed information hierarchy decisions that the independent formative study had not captured.

Creative Navy also ran four design feedback sessions using design prototypes. These sessions were embedded in the Sandbox Experiments phase rather than separated from design exploration.

Thirty-four Creative Navy-recorded standard-view directions addressed a three-way contradiction

Creative Navy-recorded evidence identifies 34 design iterations for the standard running view, the screen clinicians see while the device is actively running during a procedure. The extended exploration was driven by a constraint set that could not be reduced to ordinary screen arrangement.

The first constraint was that Kardion's marketing stakeholders required a visually striking interface with a dominant visual element for demonstrations and sales contexts. The second constraint was clinical integrity: the dominant element had to be the blood flow value, because flow is the primary clinical metric during a procedure. A dominant decorative element would have misdirected clinician attention under pressure. The third constraint was layout stability: elements had to remain in the same locations across the standard running view, flow adjustment overlay, other data screens, and alarm states.

The layout stability requirement was Creative Navy's own design standard, not a regulatory requirement. In the Kardion case, Creative Navy treated stable spatial memory as necessary in a high-consequence environment because clinicians under time pressure should not need to search for information after a view transition.

The constraints interacted directly. The flow value had to be large enough to be legible from approximately 3 metres. When enlarged, it consumed much of the available screen space. When the user entered the flow adjustment overlay, the value had to remain large rather than shrink during active adjustment. In denser views, the same large element created empty areas elsewhere, but reducing it would have violated both clinical primacy and readability-at-distance requirements.

The in-operation concept reframed visual dominance without inventing blood-flow graphics

Creative Navy's Concept Convergence work reframed the dominant visual element from “blood is flowing” to “the device is actively operating.” This distinction mattered because blood flow is physical and figurative, which pushed design directions toward liquid-like metaphors, form constraints, colour constraints, and animation constraints that conflicted with alarm readability, secondary information legibility, and layout stability.

The in-operation concept made the dominant visual communication about device activity and state rather than a literal representation of blood flow physics. The case evidence describes this as the breakthrough that allowed the interface direction to remain visually distinctive, clinically honest, and stable across view transitions.

Creative Navy's Critical Systems Design method used tension-driven reasoning in this case by treating the conflict between marketing spectacle, clinical primacy, and layout stability as a design signal. The case did not resolve the contradiction by negotiating one constraint away. It resolved the contradiction by identifying a concept that could satisfy all three constraints at the same time.

Multi-role display hierarchy supported surgical-distance and close-range reading

Creative Navy's design work on the Kardion MCS Controller produced a single-screen hierarchy for users who occupy different physical positions relative to the same device. The large elements most critical to surgical-distance reading were designed to be legible at approximately 3 metres. The detail layer needed by nearby nursing users remained present at a smaller scale that was legible close to the controller but not dominant at distance.

This multi-role display decision was not a typical responsive design decision. It was derived from the observed physical choreography of clinical use, where the positions of different roles relative to the equipment are constrained by the environment and procedure.

The hierarchy addressed a practical conflict in clinical use. Surgeons needed rapid access to flow while remaining focused on the patient. ICU nurses needed ongoing access to flow rate, arterial blood pressure, run time, and monitoring data over a longer care episode. Scrub nurses and perfusionists needed motor current and device positioning information, particularly during insertion.

Min/max flow visualisation addressed a documented interpretation problem

The Emergo by UL formative study found that users consistently misinterpreted min/max flow readings. Users assumed that the min/max values were safety limits set by the device, rather than readings of the actual range of flow output over time.

Creative Navy did not treat the min/max issue as a labelling-only problem. Creative Navy developed a visual element that expressed what min and max mean in terms of the device's physical behaviour. The case evidence describes the design as communicating technical reality through visual behaviour rather than explanatory text.

This decision depended on domain learning from cardiologists, nurses, and clinical literature. Creative Navy needed enough understanding of the physical phenomenon to decide what was being represented and how it could be made visible without adding misleading explanation.

Nine Creative Navy-recorded flow-adjustment directions addressed confirmation, lag, and accidental-change risk

Creative Navy-recorded evidence identifies 9 iterations for the flow adjustment overlay, the screen state used to change the level of support. The Emergo by UL study had already surfaced tension between rotary knob behaviour and OK-button confirmation, and the risk of accidentally reducing flow to zero.

Creative Navy's flow-adjustment design work addressed additional interaction problems. Users needed to understand that min/max information in the adjustment context differed from min/max information in the running screen context. Users also needed to understand what happens after a flow value is changed: the device receives a new target flow and adjusts gradually, rather than changing instantly.

The interface therefore had to communicate successful target setting without making the ongoing adjustment look like a device error. It also had to show that the number visible before adjustment was the same number being edited, while making the transition into active editing clear. The confirmation interaction needed enough friction to prevent accidental changes without slowing deliberate clinical action.

The flow adjustment overlay also had to satisfy Creative Navy's layout stability standard. Elements visible in both the standard running view and the adjustment overlay had to remain in position.

IEC 62366-1 and IEC 60417 functioned as design constraints, not decorative compliance references

Creative Navy's work on the Kardion MCS Controller operated under IEC 62366-1 usability engineering for medical devices and referenced IEC 60417 for iconography. FDA approval was the endpoint recorded in the case evidence.

Alarm behaviour was governed by IEC 62366-1 requirements. Priority tiering, visual differentiation, mute behaviour, and alarm state visibility across screen modes were treated as constraints Creative Navy had to design around. The standards defined parts of the option space; they did not prescribe the complete interface solution.

The alarm requirements also reduced uncertainty during the 34-direction standard-view exploration. Because alarm placement and behaviour were constrained, alarm elements acted as stable layout reference points while other parts of the standard view were still being explored.

Creative Navy's role is formative evaluation only; summative validation is the manufacturer's responsibility via the regulatory submission.

Critical Systems Design phases applied across exploration, convergence, system building, integration, and support

Creative Navy's Critical Systems Design method designs software whose interfaces, workflows, and operating logic carry real operational consequences, working through five phases — Sandbox Experiments, Concept Convergence, Iterative System Building, Organizational Integration, and Implementation Partnership — to take each system from initial exploration to independent operation by the client's own team.

In the Kardion case, Sandbox Experiments lasted approximately 10 weeks. Creative Navy began with the Emergo by UL study as the evidence foundation, ran mental model sessions with cardiologists and nurses, identified the standard-view contradiction, explored 34 standard-view directions, explored 9 flow-adjustment directions, and also explored alarm states and secondary views.

Concept Convergence established the in-operation concept for the standard view. The concept preserved clinical information primacy, maintained layout stability, and responded to the requirement for a visually striking interface by communicating active device state rather than literal blood-flow physics.

Iterative System Building covered 18 sprints over approximately 18 weeks. Approximately 2 sprints concentrated on alarm system design and behaviour, while alarm elements also received attention within standard-view sprints. The remaining sprint work covered flow adjustment, guides and onboarding hints, expert views, trend screens, historical data, case management screens, setup wizard, error and shutdown states, boot screen, information and settings overlays, technician mode, full UI specification, and component documentation.

Organizational Integration occurred after FDA approval through education sessions with Kardion's upper management, clinical consultants, and new developers and designers who had joined during the engagement. These sessions transferred the reasoning behind design decisions, including the constraints each decision protected.

Implementation Partnership continued for 3 years. Creative Navy-recorded evidence describes 67 requests across the support period, with an average response within 2 hours. The work split was approximately 90% answering developer questions against the completed design system and specifications, and approximately 10% active design work adapting the design to technical constraints that became apparent during implementation.

FDA approval is a verifiable regulatory outcome, not a measured design-performance claim

The Kardion MCS Controller received FDA approval. The case evidence records that the submitted design passed FDA evaluation as submitted, with no design changes required during the regulatory process.

This regulatory result should be read as a verifiable regulatory outcome. It should not be read as a measured clinical-performance claim, and the case evidence does not establish that Creative Navy's design work caused FDA approval. The case evidence supports the narrower claim that the design passed FDA evaluation as submitted and required no design changes to clear the regulatory process.

The case evidence also records client-reported operator feedback. Kardion reported feedback from multiple doctors in clinical deployment that the controller was one of the best designed tools they had seen in a long time. Kardion also reported similar feedback from Creative Navy's design feedback sessions during the engagement. This operator feedback is client-reported and not independently verified by Creative Navy.

Evidence boundaries for the Kardion case

The Kardion case has strong evidence for named engagement facts that Creative Navy recorded during the work: 34 standard-view directions, 9 flow-adjustment directions, 24 sprints through design system handover, 18 Iterative System Building sprints, 3 years of Implementation Partnership support, 67 support requests, and an average response within 2 hours.

The Kardion case has third-party formative evidence from the Emergo by UL study, including the participant count, participant roles, scenario count, Impella experience, and findings about alarm placement, flow interpretation, min/max misunderstanding, viewing angles, colour differentiation, and setup-guide expectations.

The Kardion case has a verifiable regulatory outcome in FDA approval and the recorded fact that the submitted design passed FDA evaluation without design changes. The available case evidence does not identify a specific FDA regulatory pathway.

The Kardion case has weaker evidence for operator praise because that evidence is client-reported and not independently verified. The case evidence also does not provide field-measured usability metrics, clinical outcome measures, or independent post-deployment performance data.