ISO 18241:2016

Overview

ISO 18241:2016 - Cardiovascular implants and extracorporeal systems - Cardiopulmonary bypass systems - Venous bubble traps - specifies requirements and test methods for sterile, single‑use venous bubble traps used to remove air from the venous line during extracorporeal circulatory support. Typical clinical uses covered include cardiopulmonary bypass (CPB), extracorporeal membrane oxygenation (ECMO), and venovenous bypass for liver transplantation. The standard defines biological, physical and performance requirements, required tests and information that manufacturers must supply (labelling, packaging and shelf life).

Key topics and technical requirements

• Scope and intended use: Devices intended to remove air entering the venous line during extracorporeal procedures (CPB, ECMO, venovenous bypass).
• Biological characteristics: Blood pathway must be sterile and non‑pyrogenic; blood‑contacting materials require biocompatibility evaluation in accordance with ISO 10993 series.
• Physical characteristics:
  • Blood pathway integrity - no leaks under specified test conditions.
  • Prime volume - volume disclosed and within manufacturer tolerances.
  • Connectors - secure connections for standard tubing sizes; accessory ports to meet ISO 594‑2 (Luer) where applicable.
• Performance characteristics:
  • Air removal efficiency - expressed as a percentage; test methods must measure gaseous microemboli (size and count) and gross air volume. Manufacturers should specify air‑challenge conditions.
  • Blood cell damage - assessment of plasma‑free hemoglobin, platelet reduction and white blood cell reduction compared with control circuits.
  • Flow rate capacity and pressure drop - demonstrated limits per manufacturer specifications.
  • Shelf life - validated and declared by the manufacturer.
• Testing and reporting: Standard provides reference test procedures (sterility, biocompatibility, integrity, air removal efficiency, hemolysis metrics, flow/pressure testing) and minimum reporting requirements to allow objective comparison across designs.
• Labelling and packaging: Required information for unit and shipping containers, accompanying documents, and prominent safety information.

Applications

• Selection, procurement and validation of venous bubble traps for cardiac surgery and critical care (CPB and ECMO).
• Design verification and regulatory submissions for medical device manufacturers.
• Performance comparison and risk assessment in perfusion practice to reduce embolic complications.

Who uses this standard

• Medical device manufacturers (design, QA/RA, clinical evaluation)
• Regulatory bodies and notified bodies reviewing device conformity
• Test laboratories conducting sterility, biocompatibility and functional testing
• Hospital perfusionists and clinical engineers for device selection and clinical protocols

Related standards

Normative references include ISO 10993 (biological evaluation), ISO 11135 / ISO 11137 / ISO 17665 / ISO 14937 (sterilization), ISO 11607 (packaging), ISO 594‑2 (Luer fittings) and ISO 7199 (respiratory connectors) - all commonly cited when demonstrating compliance for venous bubble traps and extracorporeal components.

Keywords: ISO 18241:2016, venous bubble trap, cardiopulmonary bypass, CPB, ECMO, extracorporeal, air removal efficiency, blood cell damage, medical device standard.