Establishing European traceability for medical measuring devices through optical absorbance liquid filters

Many medical measurement devices, such as biochemical and immunological analysers, rely on the measurement of optical absorption spectra. Traditionally, optical absorbance equipment has been calibrated and verified using optically neutral glass filters, but these are not always suitable for certain medical set-ups. Optical absorption liquid filters can act as an alternative but there is a capability gap in their manufacturing, characterisation and use, leading to a lack of traceability. Regulations such as EU 2017/746 on in vitro diagnostic medical devices and standards such as ISO 15189:2022 require medical measuring devices to be verified and calibrated, but not all European National Metrology Institutes (NMIs) and Designated Institutes (DIs) have the necessary capabilities or access to appropriate reference materials.

This project will help to bridge this gap by developing low-uncertainty, traceable measurement capabilities for optical absorption liquid filters in emerging NMIs and DIs, carrying out an interlaboratory comparison to establish equivalence between the new systems. It will also determine minimum criteria for absorbance liquid filters used as reference materials and produce Good Practice guidance for the manufacture, characterisation and use of optical absorbance liquid filters. This work will ensure that medical devices using optical absorption can be traceably calibrated, improving the accuracy of clinical measurements and improving treatment outcomes for patients.