Page 32 - Safety Risk Management for Medical Devices

The Basics 11

Table 3.1 (Continued)
Term Definition

Serious Injury injury or illness that: [9]
a. is life threatening,
b. results in permanent impairment of a body function or
permanent damage to a body structure, or
c. necessitates medical or surgical intervention to prevent
permanent impairment of a body function or permanent
damage to a body structure
NOTE Permanent impairment means an irreversible impairment
or damage to a body structure or function excluding trivial
impairment or damage.
System a combination of products, either packaged together or not, which
are intended to be inter-connected or combined to achieve a
specific medical purpose [2] article 2 (11)
User any healthcare professional or lay person who uses a device [2]
article 2, (37)

3.1.1 Further elaborations
Harm Although not explicitly stated in the Standard [3,7] the intention behind
including damage to property and the environment in the scope of Harm, is to
consider the type of damage that could have safety consequences. For example,
improper disposal of radioactive isotopes in a brachytherapy device may endanger
sanitation workers. In addition, with today’s environment of cybersecurity concerns,
data should be included in the scope of ‘property’.
Safety [1] advises to avoid the use of the terms “safety” and “safe” as descriptive
adjectives because they could be misinterpreted as an assurance of freedom from risk.
For example, “safety helmet” may mislead a person that wearing a safety helmet will
protect the wearer from all head injuries. All medical devices carry a certain amount
of residual risk, and the users should be made aware of such residual risks.
Risk Although the definition of risk is simply “combination of the probability of
occurrence of harm and the severity of that harm”, there are many factors that play
a role in the level of risk which is experienced by people. For example, exposure to a
hot object causes burns. But it matters how hot the object is, how long the hot object
contacts the person, where on/in the body the hot object contacts the person,
and the physical properties of the hot object compare a hot spoon vs. hot oil. Also,
typically when a Harm happens, actions are taken to ameliorate the Harm. ISO/IEC
Guide 51 [1], 3.9, Note 1, advises that in risk calculation the possibility to avoid or
limit the Harm should be included.
Hazard Analysis vs. Risk Analysis Sometimes, the terms ‘Hazard Analysis’ and
‘Risk Analysis’ are used interchangeably. This is incorrect. The purpose of hazard
analysis is the identification of Hazards and the foreseeable sequence of events that
could realize those Hazards. In contrast, risk analysis is about estimation of the