Risk Management in MedicalDevices: Hazard Identificationand Verification of MitigationControls

Abstract: During this project, the risk management of a medical device under development that deals with drug administration has been done. The aim of the project is to evaluate if part of the device is safe according to the current regulations in Sweden. The complexity of the risk management processes, particularly in healthcare, together with the lack of standardised methods to develop these kind of processes leads to a need of new tools to reduce the time, resources and complexity in this stage of the development. That is why two tools have been used and tested in order to assess the suitability under medical device development regulation conditions: the Hazard Ontology (HO) and a Fault Injection System(FIS). HO is a novel tool used to identify all hazards and threads from a predefined system in a structured way. On the other hand, FIS is a testing technique that aims to help with the study of systems when they are under faulty conditions. To ensure that the current regulations in Sweden regarding medical device are fulfilled, the EN ISO 14971 has been used as a guide for the methods applied during the work. The results of the project are exposed for every step of the process. At the end, the main result of the risk management process is a list of the mitigation measures that must be included as safety specifications of the device. Both tools, HO and the FIS, have proofed to be suitable with the current regulations as well as being useful for the process. HO gave as output a list of the main hazards of the system and the FIS have been used in the verification step of the mitigation measures. Three mitigation measures to test with the FIS has been chosen. They deal with faults regarding a speed sensor, a potentiometer and the PWM signal controlling the motor. The mitigation measures have been verified for both PWM signal and the potentiometer faults. However ,a faulty condition that leads to an unsafe behaviour has been found for the speed sensor. Therefore, we demonstrated that the medical system under study has still many control measures to implement, verify or improve before it can be said that it is a safe medical device.