Interpreting "misuse" when assessing Hazardous Situations

blah01

Involved In Discussions
Hello all,
I have some questions regarding interpretation of the requirements related to EN ISO 14971:2012 (I use ‘ISO 14971’ interchangeably below) and ISO 62304:2006. Note that I am fairly new to the Cove; I posted 1 question last year and couldn't even figure out how to find it again on the site...a bit pathetic on my part I guess :bonk:...

I have spent nearly 2 days reading through the many posts on these standards to make sure I didn't simply throw out questions that were answered already, and found it to be very informative, although I still have a couple of questions left over which I would greatly appreciate some guidance on.

First as background information, we are a North American manufacturer and our product is a stand-alone software which is considered "aids for disabled/handicapped people", per definition "2.9 medical device" Note 2 in ISO 14971:2012, and which we have classified as a Class A device under ISO 62304. We are compliant to ISO 62304 and are now in the process of implementing EN ISO 14971:2012 since we will be selling in Europe. Note that I am also familiar with the Essential Requirements in MDD 93/42, of which the relevant requirements are addressed by Annex ZA in EN ISO 14971.

My questions are as follows:
1) One of my main questions is in regards to interpreting "misuse" when assessing hazardous situations. The Medical Device Regulation, section 2.1 indicates that "The first requirement of the ‘Essential principles of safety and performance of medical devices’...when used under the conditions and for the purposes intended...they will not compromise...". So in other words, it intimates that hazards/hazardous situations should be identified and analyzed based on the intended use of the product (that's my interpretation anyhow). This is the approach we took when we defined the safety classification of our product under IEC 62304. However, ISO 14971 says that "...The manufacturer shall document the intended use and foreseeable misuse...". How far are we supposed to go in identifying misuse? For example, you can develop a prosthetic leg intended to aid with simple daily activities such as walking, but if a user then decides to go rock climbing because the prosthetic has given him a greater sense of confidence (and false confidence), then he goes and falls off the cliff because the prosthetic broke off or slipped (due to being exposed to stress beyond what it was designed for); keep in mind that proper use of the product and the intended daily activities they are intended for would be clearly described up front. This would be a misuse of the product, but, is it a misuse we need to identify during our risk analysis? We don't control what people go out and do with the aid of the product. I would like to limit ‘misuse’ to things like not properly attaching the prosthetic (and resulting consequences), and thus staying within the scope of our intended use statement. Is this acceptable?
 

somashekar

Leader
Admin
blah01.. Your example is good. Certainly that is a part of the foreseeable misuse. Playing football or doing the long jump can also be such. If its foreseeable, it is in, as far as you can foresee. Please note that the major part of this misuse information documentation gets into the device IFU. Information provided to the patient / user is a very vital risk elimination step.
 
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