Comparison of bench test results measuring the accuracy of peak flow meters

BACKGROUND: The study evaluates and compares the accuracy of nine peak flow meters (“PFMs”) and spirometers that are currently available in Europe and have Conformité Européene (“CE”) marking. The CE marking is a manufacturer’s declaration that their product complies with European health regulations and it is a requirement for marketing medical devices in Europe. METHODS: The nine devices were selected as they all had received or were in the process of receiving CE approval in Europe and were readily obtainable. The devices were bench tested following the ISO 23747:2015 accuracy guidelines for medical devices measuring peak flow. All standards, including accuracy, from these guidelines must be met to obtain CE marking. This study was performed with a certified piston pump testing apparatus. The apparatus chosen was the pulmonary waveform generator manufactured by Piston Medical Ltd. Using predefined flow (time) and volume (time) waveforms, peak flow meters and spirometers were tested for validation and calibration. Three CE guideline tests were utilised, and standards require that all three tests are passed for the device to obtain certification. RESULTS: Of the nine devices that were tested, two passed and seven failed. The devices that passed the tests were the Smart Peak Flow® and the Mini Wright®. CONCLUSIONS: A high percentage of devices failed accuracy testing in this study. This is a concern as the CE marking is a manufacturer’s certification documenting the accuracy, reliability and safety of devices. Of the seven devices that failed all have the CE marking. All tested devices are on the market in Europe based upon studies conducted by each of the manufacturers. The data used to obtain CE certification of these devices, however, are not in the public domain.