For patients recovering from knee surgery, every day counts. Their rehabilitation depends on precise, uninterrupted monitoring. But the manufacturer faced a looming threat. Critical hardware parts had reached end-of-life (EOL) or were no longer recommended for production (NRND). Without viable pin-compatible replacements, even a minor change risked forcing a full redesign—delaying production, increasing costs, and triggering costly
At the same time, the company wanted to introduce wireless (FDA re-approvals. Qi-standard) charging to enhance usability for patients. While this feature promised greater convenience, it introduced electromagnetic interference (EMI) and technical complexity to an already fragile situation.
The company stood at a crossroads: abandon the device, rebuild it from scratch, or extend its life through innovation. Time, compliance, and patient outcomes hung in the balance.
Zimetrics partnered with the client to transform this crisis into an opportunity. The first step was a deep diagnostic phase, mapping every component, firmware dependency, and manufacturing constraint.
The goal was clear: extend the product’s lifecycle while adding wireless charging without disrupting FDA compliance or patient experience.
The solution roadmap combined hardware renewal, firmware modernization, and EMI-safe wireless integration—underpinned by proactive supply-chain management.
Zimetrics identified drop-in alternatives for EOL parts, migrated legacy firmware to a stable and documented platform, and designed a wireless charging system that preserved regulatory compliance. Dual-sourcing critical components ensured production continuity and reduced future risk.
Zimetrics engineers began with a complete teardown of the existing device — from PCB layout to sensor calibration behavior. Using schematic cross-mapping and dependency tracing, the team identified more than 60 EOL or NRND components affecting sensing, BLE communication, and power management circuits.
Each dependency was categorized by form-fit-function risk to ensure downstream design decisions didn’t compromise FDA 510(k) clearance
The team built a validated matrix of drop-in alternatives that maintained the device’s form, fit, and function without requiring FDA re-approval. Each replacement underwent rigorous testing for electrical performance and compatibility to safeguard medical-grade reliability.
Firmware standardization came next. The legacy code was migrated to a stable, documented Nordic Semiconductor SDK v14.2.0 to ensure long-term stability and maintainability while enabling wireless charging integration.
Integrating Qi-standard wireless charging introduced new challenges. Zimetrics used near-field EMI scans and Design-ofExperiments (DoE) methods to optimize shielding and component placement, ensuring sensor accuracy was not compromised.
More than 250 upgraded devices were produced with dual-sourced components. Automated testing and data logging
guaranteed consistency and reliability. Running engineering, testing, and manufacturing in parallel compressed delivery timelines while maintaining quality standards.
Zimetrics turned what could have been a costly redesign into an opportunity for innovation. Their approach saved us months while preserving compliance and strengthened the device for years to come