The relation between patient benefit and risk has to be justifiable to the current state of the art. A risk assessment for every medical product has to be done, including the steps of analysis – risk assessment - mitigation - re-assessment – checking if the remaining risks are acceptable, then validate or look at the whole design again.
The risk assessment looks for risks for patients, users, third parties and the environment. Risks can appear during normal operations, in case of failure as well as during standby, storage or accidental damage. Everything that can cause a risk and the possible outcomes of these risks must be investigated and documented.
The estimation of the probability of damage and the seriousness of harm for every single risk will be done after the analysis. If the classification does not show a justifiable risk, mitigation measures have to be worked out.
The following principles should be applied in this order:
- Eliminate or minimize the risks by intrinsic safety,
- Take adequate precaution including warning systems for risks which can’t be eliminated
- Inform the users about the remaining risks for which no appropriate (adequate) precaution could be found (training, user manual, etc.).
If the effectiveness of the mitigation measures is verified, the remaining risk has to be assessed. If it is still too high, an adjustment of the risk mitigation is needed. A full cycle of the risk management cannot be completed until all risks are classified as “justifiable”. It is necessary to repeat the pass cyclic during the industrialization phase of a medical product as well.
The central standard for the development and the assembly of a medical product in Europe is the Guideline 93/42 EWG. The basic requirements are described in the appendix 1 of this guideline, and the manufacturer and the distributor of a medical product have to adhere to the guideline. This can be done by respecting all relevant harmonized standards and regulatory directives and by an approval from the “notified body”. Harmonized standards will substantiate the legal basic requirements and can be product-specific or describe general procedures and requirements.
It is not compulsory to follow the standards but is very advisable. The manufacturer has to prove sufficient safety and product performance according to the current state of the art in case of standard deviations or missing of appropriate standards. In single items, deviations of the existing standard may be important – particularly for innovative products and technologies. The required clarifications, e.g. for validation or product comparisons can be very extensive.
Single paragraphs of the appendix 1 of the guideline should be analyzed and annotated with experience from practice.
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