Evaluation (Validation and Verification) - Medical Device Design: Innovation from Concept to Market - page 219

9.3.2.6 Cleaning and Sterilization
Even though your device may be supplied nonsterile you will still have to demonstrate that
it can be cleaned and sterilized (if required) by clinical staff. In most cases you will need
to supply a certificate to say so. Each country has its own standard cycles for cleaning and
sterilization; there is equivalence but you need to be sure that your stated cleaning and
sterilization process actually produces a clean and sterile device. While it is tempting to put
this into the hands of a commercial sterilization service it is better to have this proved in the
actual environment. Hence if your device is to be cleaned and sterilized in the home, that is
where you conduct the test…not in a sterile, clean room!

Some things you may wish to consider are:

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Does your device fit into standard washing equipment?

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Does the cleaning process affect your device?

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Do you have any closed holes where detritus can lodge?

9.3.3 Calibration
In many situations, and even before any testing can start, system calibration may be required.
In instances where your device makes a measurement, calibration is, most certainly,
mandatory. However, the lessons of calibration make the verification of output to input very
credible in comparison to any ad hoc methodology. Calibration is a very easy concept if
treated with respect; if it is treated in a condescending manner it will come back to bite you.

Calibration is concerned with the referencing of measurements back to international standards
of measurement. So, for example, if your device were to measure body weight in kg it should
refer to the international standard kg held in France. Clearly you cannot fly to France for
every calibration, so each country houses its own standard kg that is referred back to the
original. These then produce their own standard kg that is housed in specialist calibration
centers based around a country so that they can be used to calibrate against. Hence when,
or if, you go to a supplier and purchase a calibrated mass from your supplier, that mass will
have a paper trail all the way back to the standard in France. This paper trail is called the
calibration ladder . The same applies to length, time, etc.

Hence the first thing to learn is

you cannot calibrate any item without first having calibrated instrumentation.

Most ISO 9001 and 13485 companies will have calibrated measurement instruments; virtually
all engineering departments in universities will have their own calibration facilities; and, of
course, there is a plethora of calibration companies. You are free to select any of these, but
you must have a calibration certificate for each instrument you intend to use.