Select materials with validated biocompatibility according to intended body contact duration and type. Use ISO 10993 certified materials — medical-grade stainless steel (304, 316L), titanium (Grade 5, Grade 23), PEEK, PTFE, silicone, and medical-grade plastics (ABS, PC, PP, PE). Avoid materials that leach toxic substances or cause allergic reactions. Maintain full material traceability from raw material sourcing to finished part.

Design parts to withstand common sterilization methods without degradation — autoclaving (steam heat up to 135°C), ethylene oxide (EtO) gas, gamma irradiation, or electron beam. Avoid crevices, blind holes, and sharp internal corners where biological matter could accumulate. Ensure smooth surfaces (Ra ≤ 0.8μm for reusable devices) to facilitate thorough cleaning. Provide adequate drainage paths for fluid evacuation.

Design with regulatory submission requirements in mind from day one. Maintain Design History File (DHF) including user needs, design inputs/outputs, verification and validation records, and risk management file per ISO 14971. Ensure traceability of all critical dimensions and features to acceptance criteria. Prepare for FDA 21 CFR Part 820 or MDR compliance based on the target market. Document all design changes with rationale and risk assessment.

Maintain high-precision tolerances (typically ±0.02mm for critical mating features, ±0.05mm for non-critical) to ensure reliable function of fluid seals, mechanical joints, and electrical contacts. Design for consistent performance across the intended lifespan. Incorporate fail-safe features where failure could cause patient harm. Conduct FMEA (Failure Mode and Effects Analysis) to identify and mitigate potential failure modes.

Design for manufacturing processes compatible with cleanroom assembly and validated production lines. Avoid undercuts and complex geometries that require secondary operations or increase inspection complexity. Specify appropriate surface finishes that balance functional requirements (friction, sealing) with manufacturing cost. Design for automated inspection where possible — incorporate datum features and optical inspection targets. Prepare Process Validation (IQ/OQ/PQ) documentation for critical manufacturing steps.