Continuing on from our case study on femoral stem implants we take a look at the chemical characterisation of a medical device that has proved invaluable during the COVID-19 pandemic: the ventilator.
Description of device
Mechanical ventilation helps move air into and out of the lungs, with the main goal of helping the delivery of oxygen and removal of carbon dioxide. It is often life saving intervention.
Specific Sample Related Considerations for Chemical Characterisation
- Material of Construction: can be higher varied, typically has to be very flexible increasing the level of chemical species
- Analytical Limits: very low due to large surface area, therefore a large amount of sample concentration is required
- Extraction Type: exaggerated as typical use up to 30 days. Additional requirements around Volatile Organic compounds
- Overall chemical characterisation complexity rating = 7

Key Factors for Chemical Characterisation
- Related Guidelines – ISO 10993-18, 18562-(parts 1-4)
- Extraction Type – exaggerated
- Solvents – 2 (polar, non-polar)
- Typical Sample Size – Very Large (200cm2)
- Extraction volume for fluid contact parts 200 mL
- Analytical Limits (without concentration) = 0.00075 µg/mL