Hello Cheryl,
It would be so nice to see into the minds of the people who are writing text to understand what they actually mean - or even better to write a nice guide explanation what they mean by some of the phrases. Oh well. How I read this is the word "calculations" could mean many different aspects or concepts, though I see it through the design and development phase. Already in section 2.3 you have text like in vitro test, mechanical tests, reliability tests, software, etc. How I read or interpret this meaning, in the context of clinical investigations, if a device is supposed to do A, B, C, D, E, F, etc., the company is able to test A, C, D, E - this leaves B and F as a specification maybe will not be fully realised until the use of the device is made in an actual patient. So as an example, if you take a non-complex device like a bone screw. There are many material and functional tests which can be performed on a bone screw including performance and in vitro tests like torsion, rigidity, bending, etc. However, when actually placed in the human body which is intended to hold together or support a bone structure, maybe there are only design calculations which can support the bone screw will do what its supposed to do when actually placed in the body, placed in bone. Therefore, when looking at information contained in Investigator Brochure, there may be specifications already known, established, and tested for a device, but maybe there are also design calculations which need to be disclosed and conveyed to the Investigator so they are aware of the parameters or use of the device. In some cases, some device's design "calculations" may already be all known. Though in other cases, these design calculations need to be explained or stated in the information so they physician or healthcare professional is aware. And of course this is all linked back to the risk management where a "design calculation" may be a residual risk until sufficient empirical evidence is gathered and analysed.
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Richard Vincins RAC
Vice President Global Regulatory Affairs
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Original Message:
Sent: 10-Sep-2020 15:54
From: Cheryl Hergert
Subject: MDR Annex XV: Chpt II, 2.3
Hello,
I have a question pertaining to MDR Annex XV: Chpt II, 2.3:
Documentation regarding the application for clinical investigation
2.3. Pre-clinical evaluation based on relevant pre-clinical testing and experimental data, in particular regarding in- design calculations, in vitro tests, ex vivo tests, animal tests, mechanical or electrical tests, reliability tests, sterilisation validation, software verification and validation, performance tests, evaluation of biocompatibility and biological safety, as applicable.
I am trying to understand what the terms 'design calculations' refers to. Any recommendations as to what this refers to and how to address this in our documentation, specifically within an Investigator Brochure, would be appreciated.
Thank you.
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Cheryl Hergert
California
United States
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