EU 2017/745 Rule 11 (re)interpretation :When Medical Device Software is classified as class III (with Example)

1. 1
EU 2017/745 Rule 11 (re)interpretation :
When Medical Device Software is
classified as class III (with Example)
Antonio Bartolozzi
antonio.bartolozzi@bartolozzi.it 12/05/2019

2. 2antonio.bartolozzi@bartolozzi.it
Rule 11
Software intended to provide information which is used to take decisions with
diagnosis or therapeutic purposes is classified as class IIa, except if such
decisions have an impact that may cause:
• death or an irreversible deterioration of a person's state of health, in
which case it is in class III; or
• a serious deterioration of a person's state of health or a surgical
intervention, in which case it is classified as class IIb.
Software intended to monitor physiological processes is classified as class IIa,
except if it is intended for monitoring of vital physiological parameters, where
the nature of variations of those parameters is such that it could result in
immediate danger to the patient, in which case it is classified as class IIb.
All other software is classified as class I
THE PROBLEM

3. 3antonio.bartolozzi@bartolozzi.it
EN 62304 : 2015 Class C
The SOFTWARE SYSTEM is software safety class C if:
• the SOFTWARE SYSTEM can contribute to a
HAZARDOUS SITUATION which results in
unacceptable RISK after consideration of RISK
CONTROL measures external to the SOFTWARE
SYSTEM and the resulting possible HARM is death
or SERIOUS INJURY.

4. 4antonio.bartolozzi@bartolozzi.it
Disambiguating MDR via EN62304
… have an impact that may cause …
… contribute to a HAZARDOUS SITUATION which results in
unacceptable RISK after consideration of RISK CONTROL
measures external to the SOFTWARE SYSTEM
and the
resulting possible HARM
is …
EN
62304:2015
EN 62304:2006 is a harmonized standards under the MDR and MDD.
EN 62304:2015 is a European Standard “carries with it the obligation to be
implemented at national level by being given the status of a national
standard and by withdrawal of any conflicting national standard".
use EN standards to interpret MDR
meaning !
DO NOT USE FOR CLASSIFICATION !
MDR
that
may
cause
impact
used to indicate possibility
or probability
a significant or major effect

5. 5antonio.bartolozzi@bartolozzi.it
Rule 11 after EN 62304:2015 filter
Software intended to provide information which is used to
take decisions with diagnosis or therapeutic purposes that is
classified as class IIa, except if such decisions can contribute to a
HAZARDOUS SITUATION which results in unacceptable RISK
after consideration of RISK CONTROL measures external to the
SOFTWARE SYSTEM and the resulting possible HARM is :
• death or an irreversible deterioration of a person's state of
health, in which case it is in class III;
• Or a serious deterioration of a person's state of health or a
surgical intervention, in which case it is classified as class
IIb.
MAY CAUSE
IMPACTdisambiguate
disambiguate

6. 6antonio.bartolozzi@bartolozzi.it
HOW classify
In determining the software safety classification of the SOFTWARE SYSTEM :
 Probability of a software failure shall be assumed lo be 1.
 Only RISK CONTROL implemented within (external to) the SOFTWARE
SYSTEM shall be considered.
NOTE Such RISK CONTROL measures may reduce the probability that a
software failure will cause HARM and/or the severity of that HARM.
EN 62304:2015

7. 7antonio.bartolozzi@bartolozzi.it
Declassify with EN62304:2015 Flow
EN 62304:2015

8. 8antonio.bartolozzi@bartolozzi.it
How declassify
For a SOFTWARE SYSTEM initially classified as software
safety class B or C, the MANUFACTURER may implement
additional RISK CONTROL measures external to the
SOFTWARE SYSTEM (including revising the system
architecture containing the SOFTWARE SYSTEM) and
subsequently assign a new software safety classification
to the SOFTWARE SYSTEM.
EN 62304:2015

9. 9antonio.bartolozzi@bartolozzi.it
External RISK CONTROL
External RISK CONTROL measures can be
hardware, an independent SOFTWARE SYSTEM,
health care procedures, or other means to
minimize that software can contribute to a
HAZARDOUS SITUATION.
EN 62304:2015

10. 10antonio.bartolozzi@bartolozzi.it
What does «class III» mean?
Class III = there is unacceptable RISK (when Probability of a
software failure is assumed to be 1) after consideration of RISK
CONTROL measures external to the SOFTWARE SYSTEM
to cause death or an irreversible deterioration of a
person's state of health.
(for every possible software bug)
Is there a unacceptable RISK - of death or
an irreversible deterioration of a person's
state of health - after consideration of
RISK CONTROL measures external to the
SOFTWARE SYSTEM?
whatever can go wrong, will go wrongApply Murphy’s Law to our software
YES CLASS III
EN62304:2015: Probability of a software
failure shall be assumed to be 1.

11. 11antonio.bartolozzi@bartolozzi.it
SOFTWARE SYSTEM
Classification Example
Therapy or radiation planning software (SW1)
Software intended to provide information which is used to take decisions with
diagnosis or therapeutic purposes
… may cause death or an irreversible deterioration of a person's state of
health …
Class III MDR
+
Safety Class C EN62304
SW1
Class C
Class III
there is unacceptable RISK after
consideration of RISK CONTROL measures
external to the SOFTWARE SYSTEM to
cause death or an irreversible deterioration
of a person's state of health

12. 12antonio.bartolozzi@bartolozzi.it
Re-Classification Example
Therapy or radiation planning software
software system (class I / IIb)
External software which check
output data (external risk control)
NO inacceptable RISK (death or an irreversible deterioration of a
person's state of health) after consideration of RISK CONTROL
measures external to the SOFTWARE SYSTEM
Class C EN62304Class B EN62304
SW1
Class B
SW1 SW2
SW2
Class C
Alarm
Segregation
software safety class
based on the risk
that the risk control
measure is
controlling .
Rule 7.7.2 EN62304:2015
Declassified
Class I (MDR)
Class I/IIb (MDR)
Paradox:
SW2 is class I (MDR)
with a safety class C
(EN62304)
Software System

13. 13antonio.bartolozzi@bartolozzi.it
WARNING !
MDR Class IIIEN 62304 Class C
USE EN 62304 ONLY TO INTERPRET AMBIGUOUS
WORDS (disambiguating)
IN MDR

14. 14antonio.bartolozzi@bartolozzi.it
Next lesson
How health care procedures could be used
as external risk control ?