approved minutes · 0900 – 1130 h thursday, 23 january 2020 motorola solutions 8000 west sunrise...

Unapproved Minutes – 8 August 2019 TC95 SC6 Meeting

Approved Minutes

IEEE/ICES TC95 Subcommittee 6 EMF Dosimetry Modeling

0900 – 1130 h

Thursday, 23 January 2020

Motorola Solution

8000 West Sunrise Blvd, Plantation, FL 33322

1. Call to Order

Chairman called the meeting to order at 0906 h.

2. Introduction of those Present

Each of the attendees introduced her/himself. (See Attachment 1 for the list of attendees.)

3. Approval of Agenda

Following a motion by Colville that was seconded by Chou, the agenda was approved as presented (see

Attachment 2).

4. Approval of the Minutes (January 2018 Meeting)

Following a motion by Ziskin that was seconded by Bailey, the minutes of the 8 August 2019 meeting

have been approved.

5. Chairman’s Report

Hirata began the Chairman’s report on the TF2: Uncertainty of Low-Frequency Dosimetry in Segmented

Models.

6. Working Group Reports

WG1 Report (See Attachment 3)

Co-chair of WG1, Alexandre Legros, provided a progress report on the activities of WG1. First he

introduced the activities of SC6 WG1 and SC3 TF1 and how both are complementary. He proceeded to summarize recommendations/findings of SC6 WG1. One important issue is to distinguish between

stimulation and subthreshold when referring to electro-stimulation. Also, it is needed reconsideration of

phosphenes as a basis of CNS limits, where there is a difference between retinal and brain neuron modulation mechanism. Also, he mentioned the literature review efforts of experimental CNS that may be

a basis to derive rheobase and corner frequencies. Alex also explained the most sensitive frequency for

phosphenes (current studies agreed in the frequency range 16-22 Hz) for transcranial current stimulation.

However, magneto stimulation may have a different sensitive frequency. He suggested that this difference needs to be investigated and clarified. He later summarized ongoing work on vestibular stimulation,

thresholds for magnetophosphenes at different conditions, and EEG source connectivity. Alex mentioned

that experimental thresholds of PNS stimulation will be considered. Also, working memory is an expression for synaptic effects and is a potential key unlock and understand more CNS thresholds. Kuster

commented on difficulties on how these experiments in brain stimulation may be translated to the

safety/standards limits of protection and that may be difficult to come out with thresholds for safety.

Legros said that the mechanisms still needs to be understand (e.g., effects of neuroplasticity of brain network changes by transcranial current stimulation) and could be eventually used. CK commented the

mission of the standard to promote safe use of electromagnetics.

WG4: Exploring the Electrostimulation Threshold in Brain (See Attachment 4)


Co-Chair, Jose Gomez-Tames, reported recent activities including the consistency of E-field computation and consistency of neuronal models for brain stimulation by transcranial magnetic stimulation exposure.

Also, dosimetry and exposure reference levels were derived using these verified models. The work was

presented at IEEE EMC2019 in Sapporo and published in IEEE T-EMC. An extended inter-comparison is

on-going, where a larger number of conditions are considered (nerve models, head models). Hirata commented that this study showed the conservativeness of the standard when considering CNS activation

in axonal response.

WG5: Definition of Incident Power Density (See Attachment 5)

Walid El Hajj (chair) gave a presentation introducing the definition of incident power density to correlate

surface temperature elevation from 6 GHz to 300 GHz to bridge the gap between IEEE C95.1 standard and the current activity of the JWG12. Also, the uncertainty that originated from the measurement’s

protocol was discussed. Preliminary results of the comparison of power density with measurements were

presented. All the results have been obtained and a technical report is under preparation. Technical report

may be published as IEEE Guidance and general paper.

Hirata further clarified that WG5 motivation is that there is not a clear definition of the power density (i.e., normal component or strength value) and clarification is worth discussing. The technical committee

responsible for Guidance should be further discussed; dependent on the content, scenarios etc. If TC95

committee is responsible for this, more members from TC95 should be involved.

TF2: Uncertainty of Low-Frequency Dosimetry in Segmented Models (See Attachment 6)

Co-chair of TF2, Rashed provide activity progress report that demonstrate the research activities since the

assignment in Aug. 2019. The main result was the study of the induced electric field within skin-to-skin contact region. The present measurement data using magnetic stimulation of the hand in different postures

demonstrate skin-to-skin touching/non-touching. Measurements demonstrate almost consistent values in

the sensation threshold values. Also, he demonstrates modeling algorithm that can be used to change

finger positions in static human models to represent skin touching/non-touching positions. Using different anatomical models, computation results of simulated magnetic stimulation demonstrate significant

increase in the computed electric field at the skin-to-skin regions. From this result inconsistency, it may be

concluded that increase of the electric field can be referred to the poor modeling and limited resolution of

the human skin in the current used human models, therefore, it might not be included within the standard.

7. New Business

SC6 will work together with SC6.

8. Time and Place of Next Meeting

The next SC6 meeting will be held on 20 Jun. 2020 in Oxford.

9. Adjourn

There being no further business, the meeting was adjourned at 11:40 h.


Attendance List

TC95 SC6 (EMF Modeling and Dosimetry): 25 January 2019, 0900-1100 h

Last Name First Name Affiliation Country IEEE SA Member?

1. Bailey Bill Exponent US Y

2. Bit- Babik Goga Motorola Solutions US Y

3. Bushberg Jerrold UC Davis US Y

4. Butcher Matt Sublight Engineering US Y

5. Chou C-K Independent Consultant US Y

6. Cleveland Robert EMF Consulting US Y

7. Colville Frank US Army PHC US Y

8. Cotton David Waterford Consultants US Y

9. Cvekovic Mario University of Split HR N

10. Diao Yingliang South China Agriculture Univ. CN N

11. Escobar Roel Air Force US Y

12. El Hajj Walid Intel FR

13. Faraone Antonio Motorola Solutions, Inc. US Y

14. Futch James Fla. Dept. Health, Radiation Contrl US N

15. Giles Olin Omni Vision Assoc. US Y

16. Glembo Tyler Intel US Y

17. Gomez-Tames Jose Nagoya Inst of Technology JP

18. Graf Kevin FCC US Y

19. Haes Donald Consultant US Y

20. Harmon Ray DoD/Navy US

21. Hirata Akimasa Nagoya Inst of Technology JP Y

22. Johnson Robert EME Safety US Y

23. Kavet Rob Kavet Consulting LCC US Y

24. Krebs Paul Verizon US

25. Kuster Niels IT’IS Foundation CH Y

26. Laakso Ilkka Aalto University FI

27. Legros Alexandre LHRI CA

28. Maxon David Istrope US Y

29. Miyagi Hiroaki HM Research & Consulting Ltd JP Y

30. Paquin Josee National Defence Canada CA N

31. Poljak Dragan University of Split HR

32. Rashed Essam British University in Egypt EG N

33. Roder Patricia IEEE SA US Staff Liaison

34. Sliney David Johns Hopkins Univ. US Y

35. Tanghe Emmeric Ghent University BE

36. Tarnaud Thomas Ghent University US

ATTACHMENT 1

ATTACHMENT 1

月


37. Tech Darang Dtech Communications US

38. Tell Ric Richard Tell Associates, Inc. US Y

39. Tong Zijun NEMA US

40. Visser Auke Royal Netherlands Navy NL N

41. Wessel Marvin Global RF Solutions US N

42. Zhao Xun DND/QETE CA

43. Ziskin Marvin Temple University US Y

44. Zollman Peter PZC UK


Agenda

IEEE/ICES TC95 Subcommittee 6 EMF Dosimetry Modeling

0900 – 1130 h

Thursday, 23 January 2020

Motorola Solutions

8000 West Sunrise Blvd, Plantation, FL 33322

1. Call to Order Hirata

2. Introduction of those Present All

3. Approval of Agenda Hirata

4. Approval of the Minutes (Jan 2019 Meeting) Hirata

5. Call for Patents* Hirata

6. Chairman’s Reports Hirata

7. Working Group Report Hirata

WG1: Uncertainties Related to Electrostimulation Threshold Legros/Laakso

WG4: Exploring the Electrostimulation Threshold in Brain Joseph/Gomez

WG5: Definition of Incident Power Density El Hajj

TF2: Uncertainty of Low-Frequency Dosimetry in Segmented Models Rashed/Diao

8. New Business

9. Date and Place of Next Meeting

10. Adjourn

Participants have a duty to inform the IEEE of holders of essential patent claims if they or their affiliations hold such claims. Check the web link on the agenda for more details. If anyone in this meeting is personally

aware of any patent claims that are potentially essential to implementation of the proposed standard(s) under

consideration by this group and that are not already the subject of an Accepted Letter of Assurance, please

speak to the committee chair today.

ATTACHMENT 2

月

IEEE ICES TC95 SC3 & SC6 - January 23rd 2020, Plantation

IEEE-ICES TC95 Winter Meeting

TF-1 – CNS Magnetic Field Exposure Limits - LFSubcommittee 6 - EMF Dosimetry Modeling

Alexandre Legros – [email protected]

Motorola Solutions Inc.Plantation, Florida21–23 January 2020

Attachment 3


Last report in Chandler winter meeting 2018

Status

For SC6 - Uncertainties Related toElectrostimulation Threshold in theELF range

§ Ilkka Laakso (co-chair)§ Alexandre Legros (co-chair)§ Akimasa Hirata§ Hideyuki Matsumoto§ Valerio De Santis§ Pat Reilly§ Tongning Wu§ Dragan Poljak§ Esra Neufeld§ Julien Modolo§ SangWook Park§ Leonardo Angelone§ Maria Iacono§ Kevin Graf

For SC3 - TF1 - CNS MagneticField Exposure Limits - LF

§ Bill Bailey§ Aki Hirata§ Ilkka Laakso§ Julien Modolo§ Alex Legros

Coordinators :

§ JP Reilly§ Rob Kavet

White paper reviewing14 electrophosphene,2 magnetophospheneand 5 dosimetrystudies

Recommendations toreduce uncertainties in

the future

Recommendations on astrategy to update LF

standards


§ Document and reduce variability in experimental thresholds for electrophosphene and magnetophosheneperceptions in the entire ELF frequency range

§ Address the heterogeneity in the methods, protocols and exposure characteristics

§ Systematic macro- and micro-dosimetry integrated to experimental studies

§ Use realistic mathematical neuronal models to question the possible mechanisms of action

§ New studies allowing a better understanding of phosphene mechanisms will reduce uncertainty

§ A clarification of the term “electrostimulation” needed:

è Stimulation refers to triggering action potentialsèModulation refers to a (subthreshold) change in membrane potential or a change in oscillation

phase for exampleè subthreshold refers to the incapability of triggering an action potential but NOT to an incapability of

eliciting biological effects

Extensive tDCS/tACS literature to take into account: measurable effects for in situ E-fields < 1 V/m (compilingdosimetry, reported neurophysiological and behavioral effects for example)

Recommendations to reduce uncertainty


§ Document experimental thresholds and mechanisms (identify meaningfulvariables/outcomes/biomarkers for reliable response to in situ E-fields)

§ Detailed dosimetry based on anatomical models

§ In situ neuro-computational models verifying the hypotheses

Phosphenes ThresholdBrain NeuromodulationThreshold (determine if

achievable)



§ Phosphene synapse modulation = mechanisms specific to the retina (graded potential neurons andribbon synapses) and not corresponding similar effects in the cortex of the brain - structural andfunctional differences

§ Outside of phosphene data, experimental evidence shows CNS effects from electro-stimulation onthe brain at levels well below demonstrable neuro-excitation in situ thresholds

§ Subthreshold CNS effectsè CNS limits should include the review of tDCS and tACS experimentaland clinical studies

§ The short deadline for editing C95.1 precludes adequate review of this literature

§ Therefore, hold CNS revision of C95.1 for implementation, and a longer-term review anddevelopment, with the objective of a more comprehensive CNS revision

Recommendations towards LF revisionShort term


§ Reconsider phosphenes as a basis for CNS limits in C95.1:

§ Differences between retinal vs. brain neuro-modulation mechanisms - rationale describing theneurophysiological retinal specificities (in structure and function)

§ Reconsider whether phosphenes per se are adverse, and whether other possibly adversereactions during phosphene experiments are credible (e.g., as suggested by Lövsund and Silny)

§ Further efforts to revise CNS limits should focus on the brain itself whether or not phosphenes arekept as the most sensitive basis for setting limits - Review should be addressed by a continuation ofTF-1 (tDCS/tACS literature), additional membership as needed – Pat contacts Marom Bikson

§ A working definition of “adverse reaction” with respect to CNS exposure is needed. A conservativedefinition might include any demonstrable CNS effect firmly established in-vivo (especially inhumans). A more focused definition of “adverse reaction” for CNS reactions should also beconsidered

Recommendations towards LF revisionLong term


§ Note: recent large sample human data the Lawson Group exhibits maximum sensitivity at 20 Hz,compared to 50, 60 and 100 Hz, although lower frequencies untested yet. However, threshold at20 Hz 2-4 times greater compared to Lövsund

§ Further development of CNS limits might result in substantial changes in C95.1 – possiblyinvolving an increase in the limits. This requires a long-term comprehensive review: anysubstantial change will require strong evidence in support of such change

§ The literature review of experimental CNS electrostimulation studies from which one can deriverheobase and corner frequency parameters.

§ This thorough review process needs to allow to reinforce/redefine DRLs and ERL forconsideration in an updated revision



§ BioEM 2019 in Montpelier

§ D’Arsonval presentation from Pat Reilly

Selected news since last report


§ BioEM 2019 in Montpellier

§ Plenary on Non-Invasive Brain Stimulation – Bikson and GrossmanMarom Bikson by Pat Reilly on IEEE ICES TF1

§ Workshop on Differences of exposure limits between the new ICNIRPGuidelines and IEEE C95.1 Standard (C-K and Eric conveners, presentationsfrom Chou, Croft, Hirata, Foster and Tell)

§ BioEM2020 in Oxford

§ Plenary on Brain Stimulation from Giulio Ruffini: Towards model-driven transcranial currentstimulation (tES 3.0): physics, physiology, modeling, and clinical applications

§ Plenary on ICNIRP / IEEE A comparison between the recently released IEEE and ICNIRPradiofrequency guidelines/standards: What are the differences, and do they make adifference? – C-K and Rodney



§ Recent new relevant activities from WG members§ Ilkka Laakso co-author of published paper:

“To validate the method, Bayesian optimization wasemployed using participants’ binary judgements aboutthe intensity of phosphenes elicited through tACS(0.25 to 1 mA)”

They used different tACS montages and confirmed a most sensitive frequency between 16 Hz and 22 Hzdepending on the montage and a given phase difference in the signals.



§ Published paper by R. Croft group involvingLegros

§ Most sensitive frequency a little above 16 HzRemark: frequency preference not consistent between electrically and magnetically induces phosphenes



§ IRPA invitation to chair of the Task Group (TG) on Non-Ionizing Radiations (NIR) of the IRPA(International Radio Protection Association - http://www.irpa.net). The general objective is topromote NIR research from national Associate Societies (AS) towards an internationalRadioprotection audience

§ Ongoing Research projects at Lawson:

§ Vestibular responses to ELF exposures up to 100 mT

§ Subjective Visual Vertical (SVV)§ Whole head exposure and posture§ Local vestibular exposure and posture (study 1 and 2)



§ Threshold for magnetophosphene perception

§ Study thresholds - analyses completed, plan to submit to Nature Biomedical engineering§ Paper 2 EEG HR source reconstruction and source connectivity submitted – Journal of

Neural engineering (lead Julien Modolo)§ Frequency response§ Adaptation to the darkness



§ Upcoming project in Rennes/Montpellier

§ Grant application to study EEG sourceconnectivity under non-invasive brainstimulations (electric and magnetic) inresting, cognitive and motor tasks (leadJulien Modolo)

§ Upcoming projects at Lawson:

§ Vestibular responses to ELF exposures up to100 mT: Vestibulo-ocular response (pupildilation and/or eyeball rotation, whole headand or Local vestibular exposure, up to 100mT (0-300 Hz)



§ Threshold for magnetophosphene perception: Replication study conducted in Montpellier-France

§ Extrapolation to synaptic processes: Test of Working Memory and associated EEG as indicatorsof modulations in synaptic plasticity (through action on LTP and LDP within the STDP paradigm)

§ Experimental Threshold for PNS stimulation a power frequencies (50 and 60 Hz)

SC6 WG1 and SC3 TF1 - common effort to conduct

Integrate recent scientific literature, results from ongoingprojects and the strength of committee members to

reduce scientific uncertainty and to methodicallyreinforce the bases of the rationale for LF standards



Thank you for your attention andhappy to be more involved with

SC3!

Alexandre Legros - [email protected]


IEEE-ICES TC95 Winter Meeting

TF-1 – CNS Magnetic Field Exposure Limits - LFSubcommittee 6 - EMF Dosimetry Modeling

Alexandre Legros – [email protected]

Motorola Solutions Inc.Plantation, Florida21–23 January 2020

Attachment 3


Last report in Chandler winter meeting 2018

Status

For SC6 - Uncertainties Related toElectrostimulation Threshold in theELF range

§ Ilkka Laakso (co-chair)§ Alexandre Legros (co-chair)§ Akimasa Hirata§ Hideyuki Matsumoto§ Valerio De Santis§ Pat Reilly§ Tongning Wu§ Dragan Poljak§ Esra Neufeld§ Julien Modolo§ SangWook Park§ Leonardo Angelone§ Maria Iacono§ Kevin Graf

For SC3 - TF1 - CNS MagneticField Exposure Limits - LF

§ Bill Bailey§ Aki Hirata§ Ilkka Laakso§ Julien Modolo§ Alex Legros

Coordinators :

§ JP Reilly§ Rob Kavet

White paper reviewing14 electrophosphene,2 magnetophospheneand 5 dosimetrystudies

Recommendations toreduce uncertainties in

the future

Recommendations on astrategy to update LF

standards


§ Document and reduce variability in experimental thresholds for electrophosphene and magnetophosheneperceptions in the entire ELF frequency range

§ Address the heterogeneity in the methods, protocols and exposure characteristics

§ Systematic macro- and micro-dosimetry integrated to experimental studies

§ Use realistic mathematical neuronal models to question the possible mechanisms of action

§ New studies allowing a better understanding of phosphene mechanisms will reduce uncertainty

§ A clarification of the term “electrostimulation” needed:

è Stimulation refers to triggering action potentialsèModulation refers to a (subthreshold) change in membrane potential or a change in oscillation

phase for exampleè subthreshold refers to the incapability of triggering an action potential but NOT to an incapability of

eliciting biological effects

Extensive tDCS/tACS literature to take into account: measurable effects for in situ E-fields < 1 V/m (compilingdosimetry, reported neurophysiological and behavioral effects for example)



§ Document experimental thresholds and mechanisms (identify meaningfulvariables/outcomes/biomarkers for reliable response to in situ E-fields)

§ Detailed dosimetry based on anatomical models

§ In situ neuro-computational models verifying the hypotheses

Phosphenes ThresholdBrain NeuromodulationThreshold (determine if

achievable)



§ Phosphene synapse modulation = mechanisms specific to the retina (graded potential neurons andribbon synapses) and not corresponding similar effects in the cortex of the brain - structural andfunctional differences

§ Outside of phosphene data, experimental evidence shows CNS effects from electro-stimulation onthe brain at levels well below demonstrable neuro-excitation in situ thresholds

§ Subthreshold CNS effectsè CNS limits should include the review of tDCS and tACS experimentaland clinical studies

§ The short deadline for editing C95.1 precludes adequate review of this literature

§ Therefore, hold CNS revision of C95.1 for implementation, and a longer-term review anddevelopment, with the objective of a more comprehensive CNS revision

Recommendations towards LF revisionShort term


§ Reconsider phosphenes as a basis for CNS limits in C95.1:

§ Differences between retinal vs. brain neuro-modulation mechanisms - rationale describing theneurophysiological retinal specificities (in structure and function)

§ Reconsider whether phosphenes per se are adverse, and whether other possibly adversereactions during phosphene experiments are credible (e.g., as suggested by Lövsund and Silny)

§ Further efforts to revise CNS limits should focus on the brain itself whether or not phosphenes arekept as the most sensitive basis for setting limits - Review should be addressed by a continuation ofTF-1 (tDCS/tACS literature), additional membership as needed – Pat contacts Marom Bikson

§ A working definition of “adverse reaction” with respect to CNS exposure is needed. A conservativedefinition might include any demonstrable CNS effect firmly established in-vivo (especially inhumans). A more focused definition of “adverse reaction” for CNS reactions should also beconsidered



§ Note: recent large sample human data the Lawson Group exhibits maximum sensitivity at 20 Hz,compared to 50, 60 and 100 Hz, although lower frequencies untested yet. However, threshold at20 Hz 2-4 times greater compared to Lövsund

§ Further development of CNS limits might result in substantial changes in C95.1 – possiblyinvolving an increase in the limits. This requires a long-term comprehensive review: anysubstantial change will require strong evidence in support of such change

§ The literature review of experimental CNS electrostimulation studies from which one can deriverheobase and corner frequency parameters.

§ This thorough review process needs to allow to reinforce/redefine DRLs and ERL forconsideration in an updated revision



§ BioEM 2019 in Montpelier

§ D’Arsonval presentation from Pat Reilly
