QUEST SPECTRUM
®
3
p. 42/50
Instructions for Use
12 Appendix C: EMC and Environmental Safety
The QUEST SPECTRUM
®
3 has been tested and found to comply with electromagnetic compatibility
(EMC) limits for medical devices to IEC/EN 60601-1-2. These limits are designed to provide reasonable
protection against harmful interference in a typical medical installation. The QUEST SPECTRUM® 3 does
not have Essential Performances as referred to in IEC 60601-1 and ISO14971 standards.
12.1 Electromagnetic interference
Medical electrical equipment requires special precautions regarding EMC and must be installed and
operated according to these instructions. It is possible that high levels of radiated or conducted radio-
frequency electromagnetic interference (EMI) from portable and mobile RF communications equipment
or other strong or nearby radio-frequency sources could result in performance disruption of the imaging
system. Evidence of disruption may include image degradation or distortion, erratic readings, equipment
ceasing to operate, or other incorrect functioning. If this occurs, survey the site to determine the source
of disruption, and take the following actions to eliminate the source(s).
❖
Turn equipment in the vicinity off and on to isolate disruptive equipment.
❖
Relocate or re-orient interfering equipment.
❖
Increase distance between interfering equipment and your imaging system.
❖
Manage use of frequencies close to ultrasound system frequencies.
❖
Remove devices that are highly susceptible to EMI.
❖
Lower power from internal sources within facility control (such as paging systems).
❖
Label devices susceptible to EMI.
❖
Educate clinical staff to recognize potential EMI-related problems.
❖
Eliminate or reduce EMI with technical solutions (such as shielding).
❖
Restrict use of personal communicators (cell phones, computers) in areas with devices susceptible
to EMI.
❖
Share relevant EMI information with others, particularly when evaluating new equipment purchases
which may generate EMI.
❖
Purchase medical devices that comply with IEC 60601-1-2 EMC Standards (3V/meter EMI
immunity, limit interference level to 0.0014 V/meter).
❖
Always use and plug in the Potential Equalizer Conductor for safe use according to 60601-1
standard.
12.2 Electrostatic discharge
Electrostatic discharge (ESD), or static shock, is a naturally occurring phenomenon. ESD is common in
conditions of low humidity, which can be caused by heating or air conditioning. Static shock is a discharge
of the electrical energy from a charged body to a lesser or non-charged body. The degree of discharge
can be significant enough to cause damage to a transducer or an imaging system. The following
precautions can help reduce ESD: anti-static spray on carpets, anti-static spray on linoleum, and anti-
static mats.
12.3 General notes and benefits of potential equalization
The voltage of a conductor or body to earth is called the "potential" of this conductor or body. The earth
is electrically neutral and thus has the potential "zero". The unit of measurement for the potential is volt.
A conductor or body has the potential "zero" (earth potential) if it is conductively connected with the earth.
As a consequence of damage to the insulation, voltages may be transmitted to metal parts which do not
belong to the service circuit. This causes the development of potentials between the metal parts which
might be dangerous for man. If a man touches two different metal parts at a time - for instance an electrical
device and a water pipe - he bridges the existing potential and current flows through his body. The flow
of electric current through the body of a human being could be mortal. A remedy for this is a potential
equalization to zero potential. Potential equalization therefore can be seen as an additional earthing (in
addition to normal earthing included in power cords) and improves the safety standard of medical devices
and medical systems. Potential equalization has the additional benefit of equal voltage potential on all
involved metal housings of medical devices of a medical system. Different voltage potentials on housings
could lead to false measurements during medical diagnosis, since the difference of voltage potential of
the medical devices within a system would interfere with voltage measurements (ECG, EMG, etc.) of the
human body. Thus, potential equalization is also important for correct and valid measurements.
