@article{KreitmeierChashinFetisovetal., author = {Kreitmeier, Florian and Chashin, Dmitri V. and Fetisov, Yuri K. and Fetisov, Leonid Y. and Schulz, Irene and Monkman, Gareth J. and Shamonin (Chamonine), Mikhail}, title = {Nonlinear Magnetoelectric Response of Planar Ferromagnetic-Piezoelectric Structures to Sub-Millisecond Magnetic Pulses}, series = {Sensors}, volume = {12}, journal = {Sensors}, number = {11}, publisher = {MDPI}, address = {Basel}, doi = {10.3390/s121114821}, pages = {14821 -- 14837}, abstract = {The magnetoelectric response of bi- and symmetric trilayer composite structures to pulsed magnetic fields is experimentally investigated in detail. The structures comprise layers of commercially available piezoelectric (lead zirconate titanate) and magnetostrictive (permendur or nickel) materials. The magnetic-field pulses have the form of a half-wave sine function with duration of 450 µs and amplitudes ranging from 500 Oe to 38 kOe. The time dependence of the resulting voltage is presented and explained by theoretical estimations. Appearance of voltage oscillations with frequencies much larger than the reciprocal pulse length is observed for sufficiently large amplitudes (~1-10 kOe) of the magnetic-field pulse. The origin of these oscillations is the excitation of bending and planar acoustic oscillations in the structures. Dependencies of the magnetoelectric voltage coefficient on the excitation frequency and the applied magnetic field are calculated by digital signal processing and compared with those obtained by the method of harmonic field modulation. The results are of interest for developing magnetoelectric sensors of pulsed magnetic fields as well as for rapid characterization of magnetoelectric composite structures.}, language = {en} } @inproceedings{KreitmeierSchulzMonkmanetal., author = {Kreitmeier, Florian and Schulz, Irene and Monkman, Gareth J. and Shamonin (Chamonine), Mikhail and Fetisov, Yuri K. and Chashin, Dmitri V. and Fetisov, Leonid Y.}, title = {Observation of Nonlinear Magnetoelectric Response to Magnetic Pulses in Layered Magnetostrictive-Piezoelectric Structures}, publisher = {IEEE}, doi = {10.1109/ISAF.2012.6297739}, abstract = {A detailed experimental study of the magnetoelectric response of planar bi- and symmetric trilayer composite structures to magnetic field pulses is reported. The structures consist of layers of commercially available piezoelectric (lead zirconate titanate) and magnetostrictive (permendur or nickel) materials. The magnetic-field pulses have the form of a half-wave sine function with duration of 450 μs and amplitude from 500 Oe up to 38 kOe. The measurement method is explained and the measured time dependence of the resulting voltage is presented. The most interesting case, when pulse amplitudes are sufficiently large (~ 1-10 kOe) and various types of acoustic oscillation with frequencies much larger than the reciprocal pulse length are excited in the structures, is considered. The dependencies of the magnetoelectric voltage coefficient on the excitation frequency and the applied magnetic field are calculated. By digital signal processing the results are compared with those obtained by the method of harmonic field modulation (HFM). The findings are of interest for developing magnetoelectric sensors for pulsed magnetic fields as well as for rapid characterization of magnetoelectric composite structures.}, language = {en} } @article{HirmerDanilovGiglbergeretal., author = {Hirmer, Marion and Danilov, Sergey N. and Giglberger, Stephan and Putzger, J{\"u}rgen and Niklas, Andreas and J{\"a}ger, Andreas and Hiller, Karl-Anton and Schmalz, Gottfried and Redlich, Britta and Schulz, Irene and Monkman, Gareth J. and Ganichev, Sergey D.}, title = {Spectroscopic Study of Human Teeth and Blood from Visible to Terahertz Frequencies for Clinical Diagnosis of Dental Pulp Vitality}, series = {Journal of Infrared, Millimeter, and Terahertz Waves}, volume = {33}, journal = {Journal of Infrared, Millimeter, and Terahertz Waves}, publisher = {Springer}, issn = {1866-6906}, doi = {10.1007/s10762-012-9872-3}, pages = {366 -- 375}, abstract = {Transmission spectra of wet human teeth and dentin slices, together with blood of different flow rates were investigated. The measurements carried out over a wide spectral range, from visible light down to terahertz radiation. The results make it possible to find the optimum light frequency for an all-optical determination of pulpal blood flow and, consequently, for clinically diagnosis of tooth vitality.}, language = {en} } @article{KnoerzerHillerBrandtetal., author = {Kn{\"o}rzer, S. and Hiller, K-A and Brandt, M. and Niklas, Andreas and Putzger, J{\"u}rgen and Monkman, Gareth J. and Danilov, Sergey N. and Ganichev, Sergey D. and Schulz, Irene and Schmalz, Gottfried}, title = {Detection of pulsed blood flow through a molar pulp chamber and surrounding tissue in vitro}, series = {Journal of Clinical Oral Investigations}, volume = {23}, journal = {Journal of Clinical Oral Investigations}, number = {3}, publisher = {Springer Nature}, doi = {10.1007/s00784-018-2530-y}, pages = {1121 -- 1132}, abstract = {OBJECTIVES Due to severe limitations of dental pulp sensitivity tests, the direct recording of pulsed blood flow, using photoplethysmography (PPG), has been proposed. In vivo evaluation is methodologically difficult and in vitro models have hitherto been adversely influenced by shortcomings in emulating the in vivo situation. Consequently, the aim of this study was to test an improved data acquisition system and to use this configuration for recording pulsed blood in a new model. MATERIALS AND METHODS We introduced a PPG signal detection system by recording signals under different blood flow conditions at two wavelengths (625 and 940 nm). Pulsed blood flow signals were measured using an in vitro model, containing a molar with a glass pulp and a resin socket, which closely resembled in vivo conditions with regard to volumetric blood flow, pulp anatomy, and surrounding tissue. RESULTS The detection system showed improved signal strength without stronger blanketing of noise. On the tooth surface, it was possible to detect signals emanating from pulsed blood flow from the glass pulp and from surrounding tissue at 625 nm. At 940 nm, pulp derived signals were recorded, without interference signals from surrounding tissue. CONCLUSION The PPG-based method has the potential to detect pulsed blood flow in small volumes in the pulp and (at 625 nm) also in adjacent tissues. CLINICAL RELEVANCE The results show the need for clear differentiation of the spatial origins of blood flow signals of any vitality test method to be applied to teeth.}, language = {en} } @incollection{NiklasHillerJaegeretal., author = {Niklas, Andreas and Hiller, Karl-Anton and J{\"a}ger, Andreas and Brandt, M. and Putzger, J{\"u}rgen and Ermer, C. and Schulz, Irene and Monkman, Gareth J. and Giglberger, Stephan and Hirmer, Marion and Danilov, Sergey N. and Ganichev, Sergey D. and Schmalz, Gottfried}, title = {In vitro optical detection of simulated blood pulse in a human tooth pulp model}, series = {Biocompatibility of Dental Materials}, booktitle = {Biocompatibility of Dental Materials}, editor = {Arenholt-Bindslev, Dorthe and Schmalz, Gottfried}, publisher = {Springer}, address = {Berlin ; Heidelberg}, language = {en} } @inproceedings{DrexlerHirmerDanilovetal., author = {Drexler, C. and Hirmer, Marion and Danilov, Sergey N. and Giglberger, Stephan and Putzger, J{\"u}rgen and Niklas, Andreas and J{\"a}ger, Andreas and Hiller, K.A and L{\"o}ffler, S. and Schmalz, Gottfried and Redlich, B. and Schulz, Irene and Monkman, Gareth J. and Ganichev, Sergey D.}, title = {Infrared spectroscopy for clinical diagnosis of dental pulp vitality}, series = {37th International Conference on Infrared, Millimetre, and Terahertz Waves (IRMMW-THz 37), 23-28 September 2012 , Wollongong, Australia}, booktitle = {37th International Conference on Infrared, Millimetre, and Terahertz Waves (IRMMW-THz 37), 23-28 September 2012 , Wollongong, Australia}, publisher = {IEEE}, address = {Piscataway, NJ}, doi = {10.1109/IRMMW-THz.2012.6380091}, abstract = {Transmission spectra of wet human teeth and dentin slices, together with blood of different flow rates were investigated over a wide spectral range, from visible to terahertz (THz) light. The results make it possible to find the optimum light frequency for an all-optical determination of pulpal blood flow and, consequently, for clinically diagnosis of tooth vitality.}, language = {en} } @inproceedings{SchulzPutzgerNiklasetal., author = {Schulz, Irene and Putzger, J{\"u}rgen and Niklas, Andreas and Brandt, M. and J{\"a}ger, Andreas and Hardt, A. and Kn{\"o}rzer, S. and Hiller, Karl-Anton and L{\"o}ffler, S. and Schmalz, Gottfried and Danilov, Sergey N. and Giglberger, Stephan and Hirmer, Marion and Ganichev, Sergey D. and Monkman, Gareth J.}, title = {PPG signal acquisition and analysis on in vitro tooth model for dental pulp vitality assessmen}, series = {2nd Applied Research Conference 2012 (ARC 2012), 25./26. June 2012, Nuremberg}, booktitle = {2nd Applied Research Conference 2012 (ARC 2012), 25./26. June 2012, Nuremberg}, publisher = {Shaker-Verlag}, address = {Aachen}, organization = {ARC}, pages = {142 -- 146}, language = {en} }