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C63-SC8

C63-SC8. October 24, 2007 Gaithersburg Maryland. SC8 Members. Joe Morrissey Steve Berger Don Heirman Dan Hoolihan Victor Kuczynski Bob Hofmann Steve Whitesell Jim Turner Steve Coston Poul Anderson Bob Jenkins Bill Stumpf (???). Matt Bakke Paul Cardinal Bob DeLisi Bill Hurst

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C63-SC8

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  1. C63-SC8 October 24, 2007 Gaithersburg Maryland

  2. SC8 Members • Joe Morrissey • Steve Berger • Don Heirman • Dan Hoolihan • Victor Kuczynski • Bob Hofmann • Steve Whitesell • Jim Turner • Steve Coston • Poul Anderson • Bob Jenkins • Bill Stumpf (???) • Matt Bakke • Paul Cardinal • Bob DeLisi • Bill Hurst • Ralph Showers • Mike Violette • Don Witters • Kendra Green • Daniel Ahlers • Massud Attaj • Ed Hare • George Hirvela • David Zimmerman • Jag Nadakuduti • Dheena Moongilan • John Lichtig • Harry Levitt • Jeff Silberberg • Jon Casamento • Mike Windler • Herb Mertel • Werner Schaefer

  3. C63™ SC8 WG1 Report ANSI C63.18: American National Standard - Recommended Practice for an On-Site, Ad Hoc Test Method for Estimating Electromagnetic Immunity of Medical Devices to Radiated Radio- Frequency (RF) Emissions from RF Transmitters

  4. Major Revision: Optional Test Methods • Representative waveforms • Recorded signal files • Actual RF transmitter (mobile phones in a test mode / radio keyed to transmit) * Deleted: mobile phone taken to an area of low signal to assume transmit at or near full power [dynamic power control makes it too variable to produce repeatable or reliable results]

  5. Additional Revision • Identifying local licensees • Obtaining proper permission / FCC STA • Look-up Table to estimate field strengths from common RF transmitters (field probe surrogate)

  6. Clause 3.3, 2nd par: • From: "If there are metal Venetian blinds on the windows, they should be closed during the test." • To “If there are metal Venetian blinds on the windows, they should be fully raised during the test. This is because prior testing has found …”

  7. Section 3.7: RF field strength meter A field probe meter is suggested in the test methods above to characterize the ambient field levels from external sources as well as characterize E-field levels from the RF transmitter at any distances where EMI events are observed with the medical device under test. Several suitable field probes are available, and should include at a minimum a dynamic frequency range for detection starting at < 100 MHz to > 2GHz. Ranges that are greater than <100 MHz to > 2GHz, so long as the probe is calibrated to operate in the range where the RF transmitter will be operating. Probes that have a range only up to 1 GHz may be used for mobile phone signals in the 824-848 MHz band, as well as for many radio technologies that transmit below 1 GHz. The probe should be isotropic, and in addition have a sensitivity of at least 30 dB below the typical power of mobile phones and radios in the near field, or a sensitivity < 1-2 V/m. If the cost of purchasing a field strength meter is prohibitive, it may be possible to rent one or to pool resourses with another organization.

  8. C63™ SC8 Hearing Aid / Hearing Loss Distributions

  9. 2002: Population > age 60 % of Populationover age 60 0-9 % 10-19 % 20-24 % 25-29 % 30+ % WW Average > 60 = 10% Source: United Nations “Population Aging 2002”

  10. 2050: Population > age 60 % of Populationover age 60 0-9 % 10-19 % 20-24 % 25-29 % 30+ % WW Average > 60 = 21% Source: United Nations “Population Aging 2002”

  11. Heterogeneity across Hearing Loss Types • Includes different magnitudes of loss, different sensitivity to parts of the audio spectrum, as well as increased background (e.g., tinnitus – objective or subjective) • General Mechanism • Conductive (blockage) • Sensorineural (damage to inner ear / acoustic nerves) • Mixed • Central Auditory Processing Disorder • Examples • Acoustic Neuroma • Ototoxicity (drug induced) • Meniere’s Disease • Otosclerosis (bone abnormality) • Hearing Loss • est. 28-35 million in US • est. 6 million / 20% wear HAs • 2% children <18 • 60-75% adults >75 • 60% of R&R Hall of Fame • Rate of hearing impairment in US increasing faster than population • Twenty percent of hearing loss patients use hearing aids • Etiology • Noise 34% • Age 28% • Infection / Injury 17% • Genetics 5% • Other / unknown 16%

  12. Approach

  13. HA distribution in the US § - HIA quarter statistics ending March 31, 2007 (Carol Rogan) † - Cathy van Evra ‡ - Sergie Kochkin MarkeTrak publications (2004 data) ٭ - newer BTE hearing aids have significantly increased immunity * - 30% ‡‡- Kyle Dennis

  14. C63™ SC8 Dynamic Power Control and Discontinuous Transmission

  15. GSM Power Step IncrementsETSI Document, GSM 5.05 version 5.10, ETS 300 910, 1996 ** new ETSI revision allows power control down to 5 dBm (0.003 W)

  16. [from Morrissey (2007), Rad Prot Dos]: Comparative power control levels associated with ~3 ½ minutes of two separate calls (in good vs. poor coverage) made on a US 1900 MHz GSM network. Peak (pulse) power can be calculated by multiplying maximal average power (125 milliwatts) x 8 *statistical models of path loss due too variable – must measure experimentally

  17. Differences may reflect 850 / 1900 MHz vs. 900 / 1800 MHz network distributions, global roaming agreements, handoff characteristics (traffic management), indoor network deployments, driving habits, home use, etc

  18. C63™ SC8 HEI Research Update

  19. Mobile Phone Exposure

  20. Kathrein panel antenna • Designed for in-building installations • Multi band with high (1710-2500 MHz) and low (806-960 MHz) band antenna elements. • Maximum input power: 50W http://kathrein-scala.com/catalog/800-10248.pdf

  21. Kathrein multiband antenna • high (1710-2500 MHz) and low (806-960 MHz) bandplexiglas casing for accurate positioning High band antenna element Low band antenna element

  22. Field uniformity 1880 MHzseparation distance = 40mm and P=1W E-field H-field 0 dB = 140.0V/m 0 dB = 0.405A/m

  23. Ongoing Antenna Design

  24. Discone Antenna Disc_radius = 20mm, Cone_length=110mm, Cone_outer_radius=35mm (I forgot to take actual pictures of the antenna before shipping it to HEI)

  25. Discone schematic

  26. Discone antenna reflection coefficient

  27. E- and H-field data

  28. Mobile Phone limits (V/m) from C63.19 (2006)

  29. E- field Plots(12mm outside cylindrical tube) 1900 MHz (70x70mm) 850 MHz (70x70mm)

  30. H- field Plots(12mm outside cylindrical tube) 1900 MHz (90x90mm) 850 MHz (70x70mm)

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