Many “no fault found” device issues may actually stem from accessories, disposables, or workflow conditions rather than the device itself.
By Rajani Kumar Sindavalam
When a medical device underperforms or behaves unexpectedly in the field, the immediate assumption is often that the issue lies within the device itself. However, in many cases, the root cause is not the device—but what is connected to it. Medical devices do not operate in isolation; they function within a broader ecosystem that includes disposables and accessories such as tubing sets, sensors, connectors, and patient interfaces.
While these components are often treated as interchangeable or secondary, they can significantly influence device performance, reliability, and safety. This extends beyond the primary hardware to include clinical workflows, user interactions, and environmental conditions.
Variability in any of these elements can influence how the system behaves, often in ways that are not fully captured during controlled testing. Understanding these interactions is essential for both healthcare technology management (HTM) teams and device manufacturers.
The Overlooked Part of the Ecosystem
Devices are designed, verified, and validated as systems. Yet in real-world use, the system extends beyond the core device to include components that may vary across vendors, lots, and usage conditions.
Disposables and accessories are frequently assumed to behave consistently, but in reality, variability in material properties, wear conditions, and compatibility can alter how the device performs. This gap between controlled testing and real-world usage introduces a class of issues that are often difficult to detect and even harder to reproduce.
How Disposables Affect System Performance
Disposables and accessories can directly influence the key performance characteristics of a device. These effects are not always obvious, and a device may appear to function correctly under standard conditions, yet behave entirely differently when influenced by variability within the ecosystem.
Take infusion systems as an example. Tubing compliance and resistance can directly affect flow delivery accuracy, while changes in backpressure can influence occlusion detection. Hospitals frequently use third-party IV tubing sets to manage supply chain costs. If the silicone in a third-party tubing set is just a fraction of a millimeter too thin or too rigid, the pump’s safety clamp might not fully occlude the line. This can introduce a clinical risk: accidental free-flow or persistent false occlusion alarms. Variability in connectors may also impact pressure sensing, compounding the issue.
Similarly, in monitoring systems, sensor quality and cable integrity can drastically affect signal accuracy. Intermittent connections can easily lead to data dropouts or clinical noise that distracts providers.
Reliability Challenges in the Field
Ask any HTM professional about their biggest frustration, and you will likely hear about the “no fault found” scenario. A device may be reported for inconsistent behavior on the floor, yet perform normally during bench testing or service evaluation.
In many situations, the device itself may function as designed, while the surrounding setup contributes to the issue. In many such cases, the issue is directly linked to worn or degraded accessories, intermittent cable issues, or the use of disposables well beyond their intended lifecycle.
Consider a situation where nurses repeatedly report a patient monitor for dropping SpO2 signals. The HTM team tests the monitor on the bench, and it passes effortlessly. The actual culprit? A reusable finger sensor that has been wiped down with harsh hospital-grade bleach wipes so many times that the optical lens is clouded, or an internal wire frayed from being wrapped tightly around the device. Because these components are often replaced, reused, or substituted before the technician arrives, identifying the true root cause becomes incredibly complex.
Safety Implications Across the Ecosystem
The impact of accessory-related variability is not merely a performance nuisance; it can directly affect patient safety. Potential risks include delayed or missed alarms due to an altered system response, inaccurate readings resulting from degraded signal quality, and therapy delivery deviations influenced by flow or pressure changes.
These are often subtle effects rather than clear device failures, making them difficult to detect during routine checks but highly significant in clinical use.
Why These Risks Are Often Missed
Traditional verification and validation activities are conducted under controlled conditions using strictly qualified components. While undeniably necessary, this approach simply does not fully capture the variability introduced in real-world settings.
Busy healthcare environments may involve multiple vendors for disposables, hasty substitutions based on inventory availability, and extended use beyond recommended limits. As a result, devices that perform reliably during testing frequently encounter unexpected behaviors when deployed within a broader, unpredictable ecosystem.
Actionable Steps for the Industry
Bridging the gap between controlled validation and real-world performance requires a shift in perspective from both sides of the aisle.
For HTM teams: Addressing these challenges requires expanding the troubleshooting approach beyond the device itself. Steps include:
- Considering disposables and accessories as part of the system during root cause analysis.
- Tracking usage patterns, including vendors and lot information where feasible.
- Correlating recurring issues with specific accessory types or environmental conditions.
- Engaging clinical staff directly to better understand real-world usage practices.
Adopting this ecosystem perspective can significantly improve the ability to identify and resolve intermittent or unexplained issues.
For manufacturers: From a design and engineering perspective, there is a distinct opportunity to better account for ecosystem-level variability. This includes:
- Evaluating system performance across a much wider range of accessory conditions.
- Risk management and verification activities should also evaluate expected variability in compatible accessories and disposables used in clinical environments.
- Defining clearer compatibility and usage guidance for end-users.
- Enhancing system logging to explicitly support field-level diagnostics.
- Treating disposables and accessories as integral elements of system behavior during the design phase.
Considering the Entire Ecosystem
Medical devices are rarely used as standalone systems. Their real-world performance is shaped by the combination of disposables, accessories, users, and clinical conditions that support them.
Recognizing these elements as integral to system behavior—not just peripheral add-ons—can help improve troubleshooting, enhance reliability, and reduce patient safety risks. In many cases, the device is not the problem; the system is. Understanding device performance, therefore, requires looking beyond the device itself and considering the entire ecosystem in which it operates.
About the author: Rajani Kumar Sindavalam is a systems engineering leader with 20 years in medical device development. He led global programs at HCLTech involving infusion pumps, peritoneal dialysis cyclers, bedside monitors, novel medical devices, and regulatory remediation across Class II/III platforms.
ID 154855718 © Serge Mikheev | Dreamstime.com
