MDR question - Meaning of Stability

[Ed Panek]

we sell a wearable thermometer. What does stability mean in this context?

 

[EmiliaBedelia]

Stability generally means the ability of the product to continue to meet its intended purpose over its intended lifetime.
In the context of measuring function, I would think of considerations like, are the markings going to wear off? does the temperature sensor have a lifetime of use that it will be valid for? is there a need for calibration or maintenance?

 

[planB]

Quote from an MSA reference:

Stability: a measure of how the accuracy and precision of the system perform over time.

 

[Ronen E]

Quote from an MSA reference:

I tried to track the source/validity, but all I found was that this definition was in the original version of the article, published in 2013 by Nicolette Young.

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[Steve Prevette]

I agree that stability is performance over the life of the instrument, and also closely related to predictability. One example may be that I take the instrument into calibration and determine it is within limits but has drifted downwards and needs to be tweaked. If over many times of performing calibrations, and it is always drifting downwards between cals, I might invoke that the instrument is not "stable". A good way to identify stability is to plot calibration results over time on a control chart.

 

[CharlieUK]

A wearable thermometer would be exposed to a much wider range of temperatures than, say, a large piece of equipment used in a medical centre, so it would be important that it's performance was also stable over temperature as well as time

 

[Ronen E]

A wearable thermometer would be exposed to a much wider range of temperatures

This was supposed to have fed into the Design Inputs through the initial Intended Use (e.g. use environment) and through Risk Management, taking account of extreme conditions and foreseeable misuse.