85
Medical electrical device (ME device)
Electrical device which is equipped with an applied part, which
serves to transfer energy to or from the patient or which indicates
such an energy transfer to or from the patient and for which the
following shall apply:
a)
The device is provided with not more than one connection to
a certain power supply network and
b)
is intended for the following use by its manufacturer:
1)
diagnosis, treatment or monitoring of a patient or
2)
compensation or palliation of a disease, injury or
disability
Patient environment
Any kind of environment where a connection can be established
intentionally or unintentionally, namely between patients and parts
of a medical electrical device or system or between a patient or
other persons touching parts of the medical electrical device or
system.
Patient leakage current
Current flowing from the patient connections via the patient to
earth or which is caused by an unintended external voltage at the
patient and flows from the patient via the patient connections of an
applied part of type F to earth.
Commissioning
Initial use of a medical electrical device or system after being
installed at the responsible organization.
Responsible organization
Entity responsible for the use and maintenance of a medical
electrical device or system (can also be a person).
Maintenance
Any kind of measures taken to preserve the condition of a medical
electrical device or system in compliance with the manufacturer's
requirements.
Applied parts (AP)
Make sure which type of applied part is concerned!
Non-observance might cause a short-circuit, e. g. in
case of an uninsulated applied part!
As an introduction, the different types of applied parts will be
described in the following. According to IEC 60601-1, an applied
part is a part of the
device
which for its
intended use
necessarily comes into physical (bodily) contact with the
patient so that the device can fulfill its function or
can be brought in contact with the patient or
needs to be touched by the patient.
An insulated (unearthed) applied part of
type F
is described as:
An applied part which is isolated from other parts of the device in
such a way that the current flowing is not higher than the patient
leakage current admissible for the
first fault
if an unintended
voltage from an external source is connected to the patient and
thus is applied between the applied part and earth.
Applied parts of type F are either applied parts of type BF or
applied parts of type CF.
For devices of protection class I, this applied part is
connected to earth which can be verified by
measurement with an ohmmeter.
Applied part of type B:
This is an applied part which provides protection against electric
shock in compliance with the requirements defined in IEC 60601-
1, especially considering the admissible leakage current, and
which is marked as follows:
Type B: earthed applied part or
Type B: applied part protected by a defibrillator
Applied parts of type B are not intended for being applied directly
to the heart.
Applied part of type BF:
This is an applied part of type F which provides a more significant
protection against electric shock than applied parts of type B in
compliance with the requirements defined in IEC 60601-1 and
which is marked as follows:
Type BF: applied part isolated from earth or
Type BF: applied part protected by a defibrillator
Applied parts of type BF are not intended for being applied directly
to the heart.
Applied part of type CF:
This is an applied part of type F which provides a more significant
protection against electric shock than applied parts of type BF in
compliance with the requirements defined in IEC 60601-1 and
which is marked as follows:
Type CF: applied part isolated from earth and
appropriate for direct application to the heart or
Type CF: applied part protected by a defibrillator
25.4
Technical terms according to VDE 0544-4
Qualified person
A person who, as a result of vocational training, sufficient experience
and knowledge of the relevant facilities, is able to evaluate and
recognize the work assigned and possible dangers.
Trained person
A person who has been instructed with regard to the work assigned
and possible dangers resulting from careless behavior.
Periodic inspection and testing
Inspection carried out at specified intervals to reduce the risk of
hazards.
Maintenance
Service carried out at specified intervals to reduce hazards and
malfunctions.
Repair
Restoring a safe and proper operating condition.
Testing personnel
Instructed person or qualified person who is trained and authorized
to carry out periodic inspection and testing.
