Classifying Medical Devices - Medical Device Design: Innovation from Concept to Market - page 14

Figure 2.2
A typical orthotic shoe insert.
Figure 2.2 illustrates a typical orthotic insert. These are foam-based structures that are
inserted into, say, the heel of a shoe to correct gait (walking pattern). They are mass produced
and are supplied nonsterile.
2.3.1 EU Classification
The EU process is a step-by-step, rule-based process. At this stage we will start at Rule #1
and work our way upward. Later we will see an alternative method.
Rule 1: All non-invasive devices are in Class I unless one of the rules set out hereafter
applies.
Basically, the rule asks us the question, “Is it invasive?” Clearly, being invasive is risky, so
one would expect invasive devices to be high risk. A noninvasive device must be less risky…
or it should be. The first part of this rule essentially says “all noninvasive devices can be
assumed to be non-risky” - the second part says in essence “but if we have evidence that its
particular use is risky then we have the right to make the classification higher.” Do not stop
here! It is tempting to, but we must work our way through all of the rules.
Q: Is our drill invasive or noninvasive?
A: The drill enters the body through a surgically made incision (there is no other way to
get at a bone). Hence it is invasive. It is NOT a Class I device.
Hopefully you get the idea. Classification is very simple if you follow the steps. It is a step-
by-step approach. In some cases, where you have not fully developed your ideas, doing a
classification analysis actually helps you to develop a specification. Thus it is worth doing at
the start. The classification may change later but we can address that later too.
Let us now consider the multipurpose orthotic shoe implant.
Q: Is it invasive?
A: An emphatic no. Hence Rule 1 states it is Class I.