Assessment of Potential Short-Term Effects of Intermittent UMTS Electromagnetic Fields on Blood Circulation in an Exploratory Study, Using Near-Infrared Imaging

Spichtig, Sonja; Scholkmann, Felix; Chin, Lydia; Lehmann, Hugo; Wolf, Martin

doi:10.1007/978-1-4614-1566-4_13

Cited by 8 publications

(5 citation statements)

References 8 publications

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“…The method comprises an algorithm based on the calculation of the moving standard deviation (to semi-automatically detect MOAs), the application of a spline interpolation to the MOA-affected parts of the time series (to reduce the MOAs), and finally the reassembly of all non-MOA-affected parts with the MOA-affected parts (to reconstruct the whole time series). The usefulness of the algorithm was shown in previous studies (Dommer et al, 2012;Holper et al, 2012aHolper et al, , 2012bHolper et al, , 2012cKobashi et al, 2012;Spichtig et al, 2012aSpichtig et al, , 2012bWolf et al, 2011b). While applying the algorithm, care was taken to ensure that no artificial new trends were introduced to the signals.…”

Section: Signal Processing and Statistical Analysismentioning

confidence: 96%

End-tidal CO2: An important parameter for a correct interpretation in functional brain studies using speech tasks

Scholkmann

Gerber

Wolf³

et al. 2013

NeuroImage

108

105

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Section: Signal Processing and Statistical Analysismentioning

confidence: 96%

End-tidal CO2: An important parameter for a correct interpretation in functional brain studies using speech tasks

Scholkmann

Gerber

Wolf³

et al. 2013

NeuroImage

108

105

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“…For further information concerning the conception of the customised NIRI sensor employed in this study, the reader is referred to Spichtig et al [2011]. The integration of the optical parts into the numerical model of the NIRI sensor does not significantly change the calculated spatial peak SAR in the head since the dielectric constants of silicone and glass do not differ much (e silicone ¼ 3.1 at 1 GHz versus e glass ¼ 3.8 at 1 GHz).…”

Section: Variability Analysismentioning

confidence: 99%

“…Therefore, a new UMTS-EMF exposure setup for a NIRS provocation study was developed. Because the NIRI study imposes many requirements to the exposure setup, we give here a brief description of the study protocol (for more details, see Spichtig et al [2011]). Healthy subjects were exposed to UMTS-like EMF of various signal forms and intensities.…”

Section: Introductionmentioning

confidence: 99%

Head exposure system for a human provocation study to assess the possible influence of UMTS‐like electromagnetic fields on cerebral blood circulation using near‐infrared imaging

Lehmann

Pollara

Spichtig³

et al. 2011

Bioelectromagnetics

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A head exposure setup for efficient and precisely defined exposure of human subjects equipped with a near-infrared imaging (NIRI) sensor is presented. In a partially shielded anechoic chamber the subjects were exposed to Universal Mobile Telecommunications System (UMTS)-like electromagnetic fields (EMF) by using a patch antenna at a distance of 4 cm from the head. The non-contact design of the exposure setup enabled NIRI sensors to easily attach to the head. Moreover, different regions of the head were chosen for localised exposure and simultaneous NIRI investigation. The control software enabled the simple adaptation of the test parameters during exploratory testing as well as the performance of controlled, randomised, crossover and double-blind provocation studies. Four different signals with a carrier frequency of 1900 MHz were chosen for the exposure: a simple continuous wave signal and three different UMTS signals. Furthermore, three exposure doses were available: sham, low (spatial peak specific absorption rate (SAR) = 0.18 W/kg averaged over 10 g) and high (spatial peak SAR = 1.8 W/kg averaged over 10 g). The SAR assessment was performed by measurement and simulation. Direct comparison of measurement and numerical results showed good agreement in terms of spatial peak SAR and SAR distribution. The variability analysis of the spatial peak SAR over 10 g was assessed by numerical simulations. Maximal deviations of -22% and +32% from the nominal situation were observed. Compared to other exposure setups, the present setup allows for low exposure uncertainty, combined with high SAR efficiency, easy access for the NIRI sensor and minimal impairment of test subjects.

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“…Signal processing was performed using MATLAB® (version 2008b, The Mathworks, Natick, MA 3,5,[19][20][21][22][23][24][25] and positively evaluated in a recent analysis comparing different movement artifact correction techniques for fNIRS. 26 Care was taken to ensure that no artificial new trends were introduced to the signals while applying the algorithm.…”

Section: Signal Processing and Statistical Analysismentioning

confidence: 99%

Cerebral hemodynamic and oxygenation changes induced by inner and heard speech: a study combining functional near-infrared spectroscopy and capnography

et al. 2014

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Abstract. The aim of this study was to investigate the effects of inner and heard speech on cerebral hemodynamics and oxygenation in the anterior prefrontal cortex (PFC) using functional near-infrared spectroscopy and to test whether potential effects were caused by alterations in the arterial carbon dioxide pressure (PaCO 2 ). Twenty-nine healthy adult volunteers performed six different tasks of inner and heard speech according to a randomized crossover design. During the tasks, we generally found a decrease in PaCO 2 (only for inner speech), tissue oxygen saturation (StO 2 ), oxyhemoglobin (½O 2 Hb), total hemoglobin ([tHb]) concentration and an increase in deoxyhemoglobin concentration ([HHb]). Furthermore, we found significant relations between changes in ½O 2 Hb, [HHb], [tHb], or StO 2 and the participants' age, the baseline P ET CO 2 , or certain speech tasks. We conclude that changes in breathing during the tasks led to lower PaCO 2 (hypocapnia) for inner speech. During heard speech, no significant changes in PaCO 2 occurred, but the decreases in StO 2 , ½O 2 Hb, and [tHb] suggest that changes in PaCO 2 were also involved here. Different verse types (hexameter and alliteration) led to different changes in [tHb], implying different brain activations. In conclusion, StO 2 , ½O 2 Hb, [HHb], and [tHb] are affected by interplay of both PaCO 2 reactivity and functional brain activity. © The Authors. Published by SPIE under a Creative Commons Attribution 3.0 Unported License. Distribution or reproduction of this work in whole or in part requires full attribution of the original publication, including its DOI.

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Assessment of Potential Short-Term Effects of Intermittent UMTS Electromagnetic Fields on Blood Circulation in an Exploratory Study, Using Near-Infrared Imaging

Cited by 8 publications

References 8 publications

End-tidal CO2: An important parameter for a correct interpretation in functional brain studies using speech tasks

End-tidal CO2: An important parameter for a correct interpretation in functional brain studies using speech tasks

Head exposure system for a human provocation study to assess the possible influence of UMTS‐like electromagnetic fields on cerebral blood circulation using near‐infrared imaging

Cerebral hemodynamic and oxygenation changes induced by inner and heard speech: a study combining functional near-infrared spectroscopy and capnography

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