COCIR Position on EU directive 2004/40/EC Umeå, 7 October 2009 Hans Baartman, Toshiba Medical...
-
Upload
lesley-lefton -
Category
Documents
-
view
212 -
download
0
Transcript of COCIR Position on EU directive 2004/40/EC Umeå, 7 October 2009 Hans Baartman, Toshiba Medical...
COCIR Position on EU directive 2004/40/EC
Umeå, 7 October 2009
Hans Baartman, Toshiba Medical Systems Europe and chair of COCIR EMF-TaskForce
page 2 of totalUmeå conference, 7 October 2009
What is COCIR?
COCIR is the European Trade Association representing European Leading companies and national trade associations
in the field of Radiology, Electromedical equipment &Healthcare IT solutions
« The European Committee for the Radiological, Electromedical and Healthcare IT Industry »
page 3 of totalUmeå conference, 7 October 2009
Range of products & services covered by the COCIR members
• Medical Imaging equipment such as– Computed Tomography– Magnetic Resonance Imaging – Diagnostic Ultrasound – Radiotherapy
• Electromedical equipment such as– Patient Monitoring– Intensive Care equipment– Electro Surgery
• Healthcare IT solutions such as – Electronic Archives, e.g. PACS– Hospital Information Systems– E-Health solutions
page 4 of totalUmeå conference, 7 October 2009
COCIR Members Today
page 5 of totalUmeå conference, 7 October 2009
Directive 2004/40/EC• Is developed to safeguard workers from adverse
effects from EMF radiation generated by the use of electric and electronic equipment.
• COCIR supports such initiative.• BUT: limits in present directive hamper the use
and further development of MR equipment and its application.
page 6 of totalUmeå conference, 7 October 2009
Exposure levels• Directive versus MRI exposure levels
Basics on MRI Technology
page 8 of totalUmeå conference, 7 October 2009
Basics of MRI• MR scanners belong to the group of Nuclear
Magnetic Resonance (NMR) equipment• Use the same principle: Tissue is seen as dipole
magnet that spins (rotate) around its axis and once such a dipole is energized it emits EMF radiation when returning to its stable state.
• With human tissue mainly containing water, MR imaging equipment concentrates itself to measure the response of hydrogen protons.
• Based on the difference in response throughout the body, tissue characterization can be performed.
page 9 of totalUmeå conference, 7 October 2009
• MRI uses 3 sections of EMF spectrum– Static field, to align all protons– Low frequency EMF, through switching gradients, to define
position and receive multiple signals from one energizing pulse
– High frequency EMF, RF, to energize protons
• Major difference between MR equipment and other equipment affected by the directive:
• MR equipment intentionally uses EMF radiation
Basics of MRI
page 10 of totalUmeå conference, 7 October 2009
Basics of MRI• Coil arrangements
zz
yy xx
Static field coilStatic field coil ((Superconducting coil)Superconducting coil)
Gz coilGz coil
Gz coilGz coil
Gy coilGy coil
Gx coilGx coil Gx coilGx coil
Gy coilGy coil Transmit coilTransmit coil
Receive coilReceive coil
Static fieldStatic field
BB00
page 11 of totalUmeå conference, 7 October 2009
• MRI is located in a controlled environment– MRI is placed in Faraday cage to avoid disturbance from
external sources like Radio, TV & GSM signals
Basics of MRI
page 12 of totalUmeå conference, 7 October 2009
• MRI is located in a controlled environment– MRI is placed in Faraday cage to avoid disturbance from
external sources like Radio, TV & GSM signals– MRI uses strong magnetic field, consequently steel objects
becomes projectiles– MRI magnet field has a stray field with restricted access to
public, because of metal implants.
Basics of MRI
page 13 of totalUmeå conference, 7 October 2009
• MRI is located in a controlled environment– MRI is placed in Faraday cage to avoid disturbance from
external sources like Radio, TV & GSM signals– MRI uses strong magnetic field, consequently steel objects
becomes projectiles– MRI magnet field has a stray field with restricted access to
public, because of metal implants. – MRI magnet is a pressure vessel filled with about 1500
Litre liquid Helium
Basics of MRI
Regulatory Framework
page 15 of totalUmeå conference, 7 October 2009
Experience combined with regulatory framework
• Over a period of 30 years, the MR community has collected a vast experience with this technology imaging over 500 million patients without evidence of harm to workers due to EMF exposure.
• MR equipment is regulated in Europe by the Medical Devices Directive 93/42/EC.
• The international IEC/EN 60601-2-33 standard is addressing the protection of patients and workers by establishing limit values for time-varying electromagnetic fields.
page 16 of totalUmeå conference, 7 October 2009
Training & work instructions
• MR equipment in hospitals, medical clinics and research facilities is always installed in a controlled environment.
• Professionals operating these installations are highly educated and received dedicated training courses on the physics behind MR imaging.
• Most of these workers are subject to a Continuous Medical Education system and therefore up to date knowledge through training and work instructions is always in place.
page 17 of totalUmeå conference, 7 October 2009
Risk assessment• Within the various system development stages
appropriate risk assessment is vital.• Such process is monitored by notified bodies as
a part of the good manufacturing practice.
• Prior to every patient examination and/or system test a risk benefit analysis is performed.
Trends in MRversus
minimizing exposure by design
page 19 of totalUmeå conference, 7 October 2009
1990 2000 20091980
MRI innovations over 30 years
0.2 T 1.5 T 3 T 7 T
page 20 of totalUmeå conference, 7 October 2009
Static magnetic fieldstrength consideration
• signal to noise ratio of the image is proportional to the static magnet field strength: S/N ~ Bo
• or (for same S/N) scan time ~ 1 / (B0)2
Example:• S/N @ 3 T= 2*S/N @ 1.5T
(i.e. twice image quality, better diagnosis)
or• scan time @ 3T=1/4 @ 1.5T
(i.e. 4 x faster -> new applications)
or• 512x512 pixel @ 3T instead of 256x256 @ 1.5T
(i.e. better diagnosis)
page 21 of totalUmeå conference, 7 October 2009
1983 1986 1990 1994 1997 2000+
Imax [A] 150 160 300 300 300 > 500
Umax[v] 120 250 300 600 800 > 2000
kVApeak 18 40 90 180 240 > 1000
Grad. Strength [mT/m] 3 10 15 20 25 > 40
rise time [ms] 1.5 1.5 1 0.5 0.4 < 0.2
Slew rate [T/m/s] 2 6.6 15 40 62 > 200
Increase of gradient performance over time
page 22 of totalUmeå conference, 7 October 2009
Theoretical options to reduce EMF exposure to MR-workers
• Options to minimize exposure to MR-worker:– reduce stray field distribution – reduce field strength opposite trend– reduce system size opposite trend
improve openness
– increase distance to field source by design disables certain
applicationsintervention, therapy, fMRI…
opposite trendto improve patient comfort
page 23 of totalUmeå conference, 7 October 2009 23
NRI’s 7.0T Human In-vivo Ultra High Resolution Image
Cellebellum
4thVentricle
Substantia Nigra
Medial Lemniscus Nucleus
Solitary Tr.Corticospinal
Tracts
Cerebral Peduncle Optic
Chiasm
OlivaryNucleus
Red Nucleues Superior Cerebella Peduncle
AnteriorCommissure
SubthalamicNucleus
Ventral Tegmental
Area
Z. H. Cho, NRI – Neuroscience Research Institute, Gachon University of Medicine & Science, Korea, 2006
COCIR View on EMF Directive
page 25 of totalUmeå conference, 7 October 2009
Applications at risk
• 50.000 MRI examinations per year in the EU hampered by current limit values :– Emergency cases (e.g. coma patients…)– Special populations (e.g. babies…)– Interventional applications
• Research and innovation like molecular imaging at manufacturing sites in Europe penalised, compared to rest of the world.
• If currents induced by movement in the static field are inside the scope of the directive, operating MR in Europe will become illegal.
page 26 of totalUmeå conference, 7 October 2009
• MR technology (existing since 1979) is responding to clinicians needs and has compiled proven benefits to citizens and patients (no evidence-based data about incidents)
• EMF generated by an MRI device is intentional, it is not a side-effect
• MR equipment is used in a controlled environment• All MR workers are trained on the possible health effects of
the exposure to EMF and equipment is designed as per IEC standard
• IEC standard is considered the “state of art” regarding safety and performance of MR equipment for patients and workers (amendment on safety of workers published in JOCE in 2008)
Reasons why MRI workers need a conditionnal Exemption
page 27 of totalUmeå conference, 7 October 2009
COCIR Recommendation• Pre-requisite:
– It is essential that MR (major advance in health care technology) is not threatened by legislation when concerns can be addressed through appropriate guidance to medical and service personnel (Guidance docoments have been developed by radiologists together with other healthcare workers)
• In view of the scientific evidence available, • In view of the specificities of the MR sector,• In view of the existing safeguards specifically developed by
IEC and CENELEC for the safety of MR equipment,
COCIR calls for a conditional exemption of MR workers considering that appropriate
training and work instructions are in place.
Thank you for your attention
More information can be found on: www.cocir.org