Overview
ISO/TR 19024:2016 provides guidance for evaluating cardiopulmonary bypass (CPB) devices by measuring their ability to reduce transmission of gaseous microemboli (GME) to a patient. The report recommends acceptable bench‑top (in vitro circulatory system) testing methodologies, describes limitations of current test methods and monitoring equipment, and outlines standardized reporting so that device comparisons are reproducible and meaningful.
Key topics and technical requirements
- Scope: Applicable to all devices intended for extracorporeal circulatory support during cardiopulmonary bypass; testing is limited to in vitro bench‑top systems.
- Test media: Recommends use of anticoagulated whole blood for more clinically relevant GME results.
- Instrumentation: Emphasizes ultrasonic bubble detectors (Doppler‑based) for GME detection and discusses detector calibration and limitations.
- Circuit description requirements: Test reports must document enough detail to reproduce the bench circuit, including:
- tubing material, internal diameter, wall thickness and length
- connector types and locations
- detector manufacturer/model and sensor placement
- pump type (roller or centrifugal) and pump specifications
- reservoir type (hard shell vs. soft bag), level and volume control
- temperature, flow rates, hematocrit, anticoagulant, isotonic dilution
- Bubble generation & reporting: Specify methods of bubble introduction (bolus vs continuous), gas composition (room air), injection site, total bubble volume, test duration, sampling schedule, and number of replicates. Report bubble counts by size and location, and calculated total gas volume; present results numerically or graphically and indicate means/variability.
- Components covered: Examples include cardiotomy/venous reservoirs, oxygenators (with/without arterial filters), standalone arterial filters, venous bubble traps, and blood pumps.
Practical applications and users
- Medical device manufacturers developing oxygenators, arterial filters, reservoirs or CPB circuit components - to benchmark GME performance and support product development.
- Independent test laboratories and R&D teams performing standardized bench‑top GME studies.
- Regulatory and clinical engineers / perfusionists who need to interpret in vitro GME data when assessing device safety or specifying system components for CPB.
- Academic researchers studying microembolism generation, removal, and the performance of mitigation technologies.
Limitations and context
- Testing guidance applies only to in vitro systems; ISO/TR 19024:2016 does not establish clinical outcome correlations. It also notes variability and calibration challenges with current ultrasonic detectors-data are most reliable for trends and comparative assessments rather than absolute GME counts.
Related standards / references
- ISO/TR 19024:2016 contains no normative references but was developed under ISO/TC 150 (Implants for surgery). Users should consult relevant device‑specific standards and regulatory guidance when integrating GME testing into product validation.