Abstracts

 

Field Medical Physics

 

 

MP 1

SOME PHYSICAL ASPECTS OF MEDICAL DIAGNOSIS METHODS USING RADIATION

 

Marta Wasilewska-Radwanska1, Artur Stepien2

 

1University of Mining and Metallurgy, Faculty of Physics and Nuclear Techniques, Al. Mickiewicza 30, 30-059 Krakow, Poland, radwanska@novell.ftj.agh.edu.pl, 2 5th Clinical Military Hospital, ul. Wroclawska 1-3, 30-059 Krakow, Poland, nucmed@citynet.pl

 

In this paper two non-invasive medical diagnosis methods using ionizing radiation such as nuclear medicine and radiology have been discussed from the physical point of view. Some physical aspects of these methods such as comparison of the absorbed dose of the patients undergoing medical examination and quality assurance of the equipment related to the recommendation of the Directive 97/43/EURATOM have been presented.

 

MP 2

USE OF LIMITED SETS OF DOSE CONVERSION FACTORS IN AN INTERVENTIONAL RADIOLOGY PROCEDURE

 

Frank Schultz1 and Johannes Zoetelief1

 

1Interfaculty Reactor Institute / Delft University of Technology, Mekelweg 15, NL-2629 JB  Delft, The Netherlands, f.w.schultz@iri.tudelft.nl

 

To assess the risk of radiological procedures the quantity effective dose (E) to the patient can be evaluated. Applying dose conversion factors (DCF) to an easily measurable dosimetric quantity, the contribution to E of each view in a diagnostic radiological examination can be obtained. DCF depend on the exposure conditions and are calculated through Monte Carlo (MC) simulation of radiation transport. In fluoroscopy guided interventional procedures DCF for typical views must substitute many similar views for practical reasons. The present study uses the MC code PCXMC to evaluate the influence on E of several excursions in the exposure conditions.

 

MP 3

DOSE CALCULATION AND ERROR ESTIMATION IN SMALL PHOTON FIELDS

 

J. Martin Jensen 1, Edzard Ihnen 2, Kirsten Eilf 3

 

1Dept. of Radiotherapy, University of Kiel Medical School, Kiel, Germany e-mail: jensen@onco.uni-kiel.de and jmjensen@web.de 2Dept. of Radiotherapy and Nuclear Medicine, University of Lübeck Medical School, Lübeck, Germany e-mail: ihnen@stnuk.mu-luebeck.de 3Dept. of Radiotherapy, University of Kiel Medical School, Kiel, Germany e-mail: eilf@onco.uni-kiel.de

 

To realize dosimetrical requirements in small-field-dosimetry especially, ionization chambers are in use. Meeting the specifications of secondary electron equilibrium the field size must not remain under specified values. As well as increasing the focus-chamber-distance, changing of physical density of the build-up-material will be helpful to determine output factors.

For bremsstrahlung of radiation by medical linear accelerators the lower limit of the field size is determined (F ł 0.8 cm), mainly depends on the diameter of the focal spot. Beside the dosimetrical aspects, geometrical parameters have to be considered, keeping dose-volume-errors as low as ±10%. The mean-total-error Δtot should not exceed ±0.8mm.

 

MP 4

COMPARISON OF COMPUTED AND MEASURED ISODOSE DISTRIBUTIONS IN PHOTON BEAM RADIOTHERAPY

 

Franco Milano

 

Dept. of Clinical Physiopathology  University of Florence

 

A Treatment Planning System (TPS) uses algorithms for external photon beam to reproduce dose deposition in the patients. It is crucial therefore to determine its accuracy before delivering treatments. All the algorithms require experimental beam data acquired in the reference condition. Because of the complexity of the beam interactions and the patient structure, the algorithms involve simplifications and therefore it is necessary to verify experimentally the TPS output. The differences in doses comparing measurements with calculations are presented. An analysis of the influence of the algorithm approximation on the TPS output is also performed.

 

MP 5

ESTIMATION OF DNA DSB RADIATION DAMAGE USING A SOLID STATE, QUASI-TISSUE-EQUIVALENT, NANODOSIMETER BASED ON GLOW PEAK 5a IN LiF:Mg,Ti

 

Leonid Oster1,Yigal S. Horowitz2, Shlomo Biderman2 , Jehuda Haddad1

 

1Negev Academic College of Engineering, P.O.B.45, Beer-Sheva 84100, Israel, e-mail: oster@bgumail.bgu.ac.il; 2Physics Department, Ben-Gurion University of the Negev, Beer-Sheva 84105, Israel

 

 We demonstrate the viability of the concept of using existing molecular nanostructures in TL solid state materials as solid-state Q/RBE equivalent nanodosimeters. The concept is based on mimicking radiobiology (specifically the ionization density dependence of double strand breaks in DNA) by using the similar ionization density dependence of simultaneous electron-hole capture in spatially correlated TC/LC pairs in the thermoluminescence of LiF:Mg,Ti. This simultaneous electron-hole capture has been shown to lead to ionization density dependence in the relative intensity of peak 5a to peak 5 similar to the ratio of DSBs to SSBs for low energy He ions.

 

MP 6

EXPOSURE OF STRONG MAGNETIC FIELD TO HUMAN TUMOUR CELL LINE HT-1080

 

Juris Rodins1, Talivaldis Freivalds2, Vadims Korhovs1, Indulis Buikis2, Liga Harju2, Tatjana Ivanova2

 

1 University of Latvia Institute of Polymer Mechanics, Aizkraukles 23, Riga, Latvia, kinetika@parks.lv, 2 University of Latvia Institute of Experimental and Clinical Medicine, O. Vaciesa 4, Riga, Latvia, freivald@latnet.lv

 

The aim was to investigate an influence of strong static magnetic field (SMF) on suppravital fluorescent probe - acridine orange (AO) uptake by human tumor cells. The cells were exposed in the space between poles with field up to 1,6 T intensity. The cell geometrical and photometrical features were measured using fluorescence microscope equipped with color CCD camera and image analysis program. SMF caused an increase of integrated red cytoplasm AO fluorescence intensity and a decrease of integrated green nuclear AO fluorescence intensity in human tumor cells. SMF stimulated cell metabolic activity, sequestration and efflux of xenobiotics.

 

MP 7

Otoacustic emission measurements of young musicians

Yuri Dekhtyar1, Ilze Jezerska2, Sandra Kuske2, Peteris Skorovs1, Janis Vetra2, Vineta Zemite1

 

1Institute of Biomedical Engineering and Microtechnologies, Riga Technical University, 1 Kalku Str., Riga,LV-1658, Latvia, e-mail: dekhtyar@latnet.lv;2 Medical Academy of Latvia, 16 Dzirciema Str. Riga, LV-1007, Latvia, e-mail: jezerska@inbox.lv

 

Otoacoustic emission (OAE) is a weak sound caused by motion of the eardrum in response to vibrations from the deep within the cochlea. OAE is a quick and non–invasive technology to evaluate inner hair cell function. The purpose of the work was to test hearing capabilities of young musicians. This was achieved by measurements of OAE tone and impedance audiometry. It was explored that OAE signals by musicians are similar to individuals working in high noise conditions. Therefore children have a greater risk of noise–induced hearing loss.

 

MP 8

Diagnostic aspects of the structural-optical bioliquids aggregation analysis

 

Elena Kononenko1, Maria Syrochkina2, Evgenie Mironov2

 

1 Ural State Technical University (USTU), 112 Vostochmaja-str.84B , Ekaterinburg, Russia, e-mai: masyal1909@hotmail.com; 2 Ural State Medical Academy (USMA), 235 Belinsky str. 132, Ekaterinburg, Russia, e-mail: mars1504@pisem.net

 

Lyotropic liquid crystal textures, crystal forms morphology and overmolecular structures alteration dynamics of different bioliquids are investigated.

Native and model lipid, lipid-protein and water-salt systems research is held by open drop and planar capillary methods along with polarization microscopy, refractometry and speckle dynamics analysis.

Test construction methodology using statistic data analysis is designed. More than 10 patent covered tests for gastroenterology, cardiorhematology, nephrology and pediatrics are created, providing additional diagnostic, treatment monitoring and prognosis possibilities.

 

MP 9

hepatobiliary system functional analysis by blood flow and clearance delay model

 

Ainars Aboltins, Eriks Reinholds

 

Riga Technical University, 1 Kalku Str., Riga,LV-1658, Latvia, e-mail: aboltins@park.lv, P.Stradins Clinical University Hospital, Riga, Latvia

 

A mathematical model on liver uptake-excretion function was developed and based on different timing delays in hepatobiliary and blood flow system elements.

The scintigraphic images with 99mTc-mebrofenin or 99mTc-HIDA from nuclear medicine gamma camera were used. The time-activity curves were obtained from the heart, liver, gallbladder, spleen, aorta, vein, etc. Both first pass and dynamic acquisition data were involved.

The calculations were compared with the real scintigraphy data and demonstrated differences of hepatobiliary system function at three main points: normal functions, good blood flow with bad hepatic function and bad blood flow with good hepatic function.

 

MPP 1

CARCINOGENIC RISK ESTIMATION OF RADIOTHERAPY OF BENIGN DISEASES

 

Jan Jansen1, Johan Broerse2, Johannes Zoetelief1 and Heinrich Seegenschmiedt3.

 

1Interfaculty Reactor Institute, Delft University of Technology, Mekelweg 15, NL-2629 JB Delft, JTJansen@iri.tudelft.nl, 2Department of Clinical Oncology, Leiden University Medical Center, P.O. Box 9600, NL-2300 RC Leiden, 3Department of Radiation Oncology, Therapeutic Radiology & Nuclear Medicine, Alfried Krupp Hospital, Alfried Krupp Straße 21, D-54117 Essen - Rüttenscheid.

 

There is a renewed interest in radiotherapy for treatment of benign diseases. Radiotherapy is reserved to malignant diseases. As ionising radiation can induce tumours, there is a need to estimate this detriment and take it into account, when comparing it to other types of treatment. The carcinogenic risk is estimated using Monte Carlo radiation transport codes and anthropomorphic phantoms to determine organ doses. From these organ doses the effective dose is derived, according to the International Commission on Radiological Protection by a weighted summation. The carcinogenic risk is determined with the high dose and dose rate risk factor of 10% per Sv.

 

MPP 2

ENERGY DEPOSITION DISTRIBUTION OF AUGER ELECTRONS EMITTED BY TECHNETIUM-99M

 

Frank Schultz1 and Johannes Zoetelief1

 

1Interfaculty Reactor Institute / Delft University of Technology, Mekelweg 15, NL-2629 JB  Delft, The Netherlands, f.w.schultz@iri.tudelft.nl

 

Technetium-99m (short half-life, low (mono) energetic gamma ray emission) is the principal radionuclide for diagnostic nuclear medicine. However, co-emission of Auger electrons may cause damage at very short range, depending on the nearby presence of radiosensitive (sub) cellular structures. In this study the distribution of energy deposition due to the Auger electrons as a function of distance from a Tc-99m point source is calculated in water, cell nucleus material and muscle, using the code MCNP for simulation of radiation transport. A bimodal distribution is found, independent of the material, with peaks at about 0.15 μm (0.05 keV/disintegration) and 4 μm (0.08 keV/disintegration).

 

MPP 3

QUALITY CONTROL IN DIGITAL FLUOROSCOPY

 

Ibrahim I. Suliman1,  Johannes  Zoetelief1

 

1Delft University of Technology e-mail: i.i.suliman@iri.tudelft.nl

In the framework of the European project DIMOND III, the document on quality control in digital fluoroscopy was drafted to offer means for equipment testing to ensure that specific requirements are fulfilled resulting in optimum image quality at minimum patient dose. The results are presented in this paper. The work involves review of documents and publications in digital fluoroscopy equipment testing. The study takes into account not only the efficiency of the tests but also their applicability in daily practice. The results are series of quality control tests and guidelines for evaluating equipment systems used in fluoroscopically guided interventional procedures.

 

MPP 4

PATIENT DOSIMETRY IN DIAGNOSTIC RADIOLOGY USING TLD

 

Johannes Zoetelief1,  Frank W. Schultz1

 

1Interfaculty Reactor Institute, Delft University of Technology, Mekelweg 15, NL-2629 JB Delft, The Netherlands, j.zoetelief@iri.tudelft.nl

 

Although expertise on patient dosimetry and appropriate technical facilities should preferably be available locally so that dose measurements can be made in house, it is recognized that dosimetric resources, such as well-trained specialists, high quality equipment and calibration facilities are not always available locally. However, appropriate assistance and dosimetric services can often be obtained from third parties. Laboratories specialised in thermoluminescent dosimetry (TLD) usually provide services in individual monitoring for radiation protection purposes and lack expertise on patient dosimetry in diagnostic radiology. Therefore, recommendations for patient dosimetry in diagnostic radiology using TLD have been made within a European concerted action

 

MPP 5

MULTICOMPONENET MEASUREMENTS OF RADIATION DOSES RECEIVED BY PATIENTS UNDERGOING COMPUTER TOMOGRAPHY EXAMINATION WITH THREE TYPE TLDs

 

H.Osmandjak1, G.Taterev2, Е.Мilieva3, А.Lichev2, М.Мitrikov4

 

1 Inter-University Centre on Medical Radiation Physics, Plovdiv, Bulgaria,2 Department of Roentgenology, Medical University(MU), Plovdiv, Bulgaria ,3 Department of Medical Physics and Biophysics, MU, Plovdiv, Bulgaria ,4 Department of Atomic Physics, Plovdiv University, Plovdiv, Bulgaria

 

The report is aimed to compare results for patients’ individual and average surface doses (CT-examination, Plovdiv) with reference dose values given by E.U. Three types of TLD: LiF(TLD-100, Harshaw), CaSO4:Dy (INRNE, Sofia) и a-Al2O3:C (UTU, Ekaterinburg, Russia), placed on patients’ thyroid gland and lumbal spine have been used. TLDs for in vivo measurement were chosen after selection for homogeneity and reproducibility (standard deviation (SD) below 5%). A correlation between surface doses from I.C. - data and TLDs - responses was observed. The results show that the individual and mean doses during CT-lumbar spine examinations are around the EU-set of norms.

MPP 6

Fibre optics scintillators and scintillation systems
for radiation monitoring of human body

Borys Shulgin, Tatyana Koroleva1, L. Zhukova, V. Petrov, D. Raikov

Ural State Technical University, 620002, Ekaterinburg,
Mira St., 19, Russia, E-mail : bvs@dpt.ustu.ru
1 Institut of Physics, National Academy of Sciences of Kyrghyz Republic,
Bishkek, Kyrghyz Republic, E-mail : koroleva@aknet.kg
 

Results on fibre optics scintillators and scintillation sistems on the basis of halides (AgCl, AgBr, AgI – Ural-light guides) for radiation monitoring of human body (for registration gamma-rays of 40K, 90Sr) are presented. The using of fibre optics scintillators in combine detectors for radiation monitoring system of human body are discussed (organic – non-organic scintillators, ionizing counter + scintillator, scintillator + semiconductor detectors). The possible using of fibre optics scintillators as scintillation optical antennas, scintillation optical dipsticks and scintillation optical cables are discussed too. Some results are done on the level of inventions.

 

MPP 7

Effect of stimulus size, luminance and task complexity on reaction time

 

Dariusz Wůodarczyk1, Piotr Jaúkowski2

 

1Department of Biophysics, Karol Marcinkowski University of  Medical Sciences in Poznań, Fredry 10, 61-701 Poznań, Poland, e-mail: wlodarda@main.amu.edu.pl

2Department of Psychophysiology, Kazimierz Wielki University of Bydgoszcz, Chodkiewicza 30, 85-064 Bydgoszcz, Poland, e-mail: piotr_jaskowski@ozzl.org.pl

 

For visual stimuli, it is usually reported that the relation between reaction time (RT) and intensity does not depend on the tasks the participants have to perform. The present study was designed to explore the effect of brightness on RT for large (8.5o deg) and small (1.7o deg) stimuli. Our participants performed RT tasks of different complexity in response to visual stimuli. The stimuli were generated by means of two LED arrays. What we found is that the task demands clearly affected shapes of the RT-intensity curves for large targets, whereas these curves were identical between tasks for small targets.

 

MPP 8

Effects from GSM Cellular Phones on Hearing

Aldis Balodis1 ,Yuri Dekhtyar1, Sandra Kuđíe2, Pçteris Skorovs1, Jânis Sokolovs2

 

1Institute of Biomedical Engineering and Microtechnologies, Riga Technical University, 1 kalku Str., Riga, LV-1658, Latvia; 2Departament of ENT, Medical Academy of Latvia, Riga, Latvia

 

The objective of this study was to evaluate effects from GSM cellular phones electromagnetic radiation to peripheral auditory system.

Distortion product Otoacoustic Emissions (DPOAEs) was used because of their relation with function of peripheral auditory system. The results achieved demonstrate that electromagnetic fields from GSM cellular phones affect amplitude of DPOAEs.

The possible Electromagnetic Interference (EMI) effects on the measurement equipment are discussed.

MPP 9

use of liver-heart time activity cross curves in hepatobiliary system nuclear imaging analysis

 

Ainars Aboltins, Eriks Reinholds

 

Riga Technical University, 1 Kalku Str., Riga,LV-1658, Latvia, e-mail: aboltins@park.lv, P.Stradins Clinical University Hospital, Riga, Latvia

 

Radionuclide scintigraphy is a popular method for functional studying of human organ systems in modern medicine. Series of scintigraphic images with 99mTc-mebrofenin or 99mTc-HIDA are taken as experimental data. The kinetics curves are taken from many regions of human body - heart, liver, gallbladder, spleen, aorta, vein, etc. Then results are represented in combined liver-heart chart. Closed system model developed and parameters calculated for that chart. Results can be used as quantitative parameters in nuclear medicine diagnostics and also in hepatobiliary system uptake-excretion function mathematical modeling.

 

 

 

Field Biomediocal Engineering and Telemedicine

 

 

BE 1

MAGNETOTHERAPEUTIC DEVICE OF COMMON INFLUENCE ON HUMAN ORGANISM

 

Sergiy Svistelnyk

 

Zhytomyr institute of engineering and technology, 103 Cherniakhovsky str., Zhytomyr, Ukraine, e-mail: sss@ziet.zhitomir.ua

 

The devices of common influence on the human organism will allow improving and creating new techniques of low-frequency electromagnetic fields taking into account the individual sensitivity of the patient. The department of automation and computer technologies of Zhytomyr Institute of Engineering and Technology is elaborating such as device, which has the following parameters: frequency range is 0,5-30 Hz, electromagnetic induction range in inductor zone is 0,05-0,5 мTesla. The design and its working principles are considered. Possible biological effects of the received fields are described.

 

BE 2

THE SYSTEM OF ELECTROSTIMULATION WITH BIOTECHNICAL FEEDBACK

 

A.N. Osipov1, S.K. Dick2, Yu.G. Degtyarev3

1 Belarussian State University of Informatics and Radioelectronics, P.Brovky 6, Minsk, Belarus, Email: osipov@bsuir.unibel.by, 2 Research Institute of Neurology, Neurosurgery and Physiotherapy, Philatova 9, Minsk, Belarus, 3 Pediatric surgery center, Scorina av. 64, Minsk, Belarus

 

In the given article “MIOS”, the multichannel device of electrostimulation with a biotechnical feedback, for the treatment of a number of movement disorders of central and peripheral origin, the correction of movements, the training of impellent skills etc. is discussed. The experimental approbation showed high efficiency of the developed device: there was a restoration not only of forces of contractions of disordered muscles, but also of lost impellent skills.

BE 3

A SOFTWARE-CONTROLLED COMPLEX FOR ELECTROMYOSTIMULATION IN THE TREATMENT OF RECTAL DISEASES

 

Anatoly Osipov1, V.M. Bondarik1, Y.G. Degtiarev2

 

1 Belarussian State University of Informatics and Radioelectronics, P.Brovky 6, Minsk, Belarus, Email: osipov@bsuir.unibel.by, 2 Pediatric surgery center, Scorina av. 64, Minsk, Belarus

 

The questions of creation of means for treatment of a rectum and anal sphincter functional frustration are considered. Joint application electrostimulation of muscles perineum and smooth muscles of large intestine with biotechnical feedback elements enables to receive higher treatment effect, to reduce reception of medicinal means, to avoid surgical treatment. The hardware-software complex for electrostimulation a rectum and anal sphincter is designed on the basis of a combination of a electrostimulation and a biotechnical feedback elements. The article describes the structure of device, design and technology of manufacturing multisegment rectal of an electrode, basic characteristics of stimulating signals.

 

BE 4

ROLE OF MEDICAL INFORMATICS STANDARDS IN BIOMEDICAL ENGINEERING AND TELEMEDICINE

 

Vytenis Punys, Jonas Punys

 

Image Processing & Multimedia laboratory, Kaunas University of Technology, Studentu 56-304, LT3031 Kaunas, Lithuania. E-mail: vpunys@mmlab.ktu.lt

 

Computer controlled medical devices have been widely used. It is essential to connect them into networks. Efficient data interchange between such devices is possible to get due to with the use of standards, creation of which accumulated the years of experience in imaging and associated information exchange and storage. The use of standards expands the field of scientific investigation and validation of results. Most widely used standards are DICOM (Digital Imaging and Communications in Medicine) and HL7 (Health Level 7). Relevant features of these standards are combined into IHE (Integrating the Healthcare Enterprise) initiative. Experience with these standards and their features are discussed.

 

BE 5

PORTABLE ECG SYSTEM FOR TELEMEDICINE 

 

Viktors Strelcs, Juris Lauznis

 

JSC “AMERILAT”, viktors@amerilat.lv , lauznis@amerilat.lv .

 

Most of portable devices for ECG transmission have limited capabilities. Presented ECG system consists of digital 12 lead ECG recorder. Pocket PC computer with software and telecommunication device like mobile phone or modem. The host end of the system is equipped with hardware and software for evaluation of ECG and result retransmission. Use of the Pocket PC makes the system flexible; different methods of data acquisition, processing, storage, data encryption and telecommunications can be used. The device has been tested on field and to transmit ECG from moving ambulance car with good results.

BE 6

HEART RATE TELEMETRY REGISTRATION UNDER VARIOUS FUNCTIONAL TESTS  

 

Natalie Bystrova1, Marina Marinina1 , Michael Sivashov2.

 

1Institute of Theoretical and Experimental Biophysics RAS, nkbys@mail.ru , 2Institute of Biological Engineering RAS, etc.

 

Functional test application allows revealing the latent functional insufficiency of organism, to estimate the state of regulatory mechanisms, and adaptive and compensatory reactions of organism. The highly tolerant to interference telemetering system for transitive characteristics of heart rate (HR) research was developed and used. 54 volunteers have taken part in 126 researches. Three types of HR reactions at realization active orthostatic test (AOT) were revealed. The data received allow assuming, that the type of HR reaction of the transient at AOT reflects the features of an organism functional state and would be expected to have independent diagnostic value.

 

BE 7

INFORMATION SYSTEMS OF TELEMEDICINE FOR THE REGIONS WITH HIGH LEVELS OF RADIATION

 

Valentyn Yanchuk1, Sergiy Svistelnyk2.

 

Zhytomyr Institute of Engineering and Technology, 103 Cherniakhovsky str., Zhytomyr, Ukraine, e-mail: 1 yank@ziet.zhitomir.ua  2 sss@ziet.zhitomir.ua

 

The necessity of the telemedicine system creation for the medical consulting of people living on the territory contaminated with radionuclides is stipulated by requirements of consulting people and well-qualified medical stuff shortage in such a region. The amount of the patients rise year by year caused by increasing of pathologies related to radiation influence on people health. The proposed system allows consulting people by means of two nodes creation: the node of investigation using Ultrasound and MRT Equipment supports the information on investigation and the node of consulting center supports the consultation on the basis of the investigation data analysis.

 

BE 8

Mathematical models for correction of images, obtained at radioisotope scan.

 

Alexander Glaz, Andris Lubans

 

Riga Technical University, Faculty of Computer Science and Information Technologies, Institute of Computer Control, Engineering and Technology. Address: Meza 1, LV-1048, Riga, Latvia. Phone: +371 7089542; E-Mail: glaz@egle.cs.rtu.lv, android@one.lv

 

The images, which obtained at radioisotope scan, contain distortions. Distortions appear as a result of absorption of radiation by patient body’s tissues. Two mathematical models for reducing of such distortions are proposed. Image obtained by only one gamma camera is used in the first mathematical model. Unfortunately, this model allows processing of the image only in case, when it can be assumed, that the investigated organ has a symmetric form. The images obtained by two gamma cameras are used in the second model. It gives a possibility to assume that the investigated organ has nonsymmetric form and to acquire more precise results.

BEP 1

POROGRAMMABLE VOLUME ECG PATTERN SIMULATOR

 

Juris Lauznis, Viktors Strelcs, Gunars Balodis

 

JSC “AMERILAT”, lauznis@amerilat.lv , victors@amerilat.lv , gunars@amerilat.lv .

 

The most disadvantage of popular low cost ECG pattern simulators is their bi-pane signal generation. This makes problematic their use in ECG interpretation software evaluation, requiring tri-dimensional presentation of signals for all 10 electrodes. Developed Programmable ECG simulator uses real heart ECG pattern, calculated from digitally acquired simultaneous 12 Lead ECG record. With the same all signal amplitudes and phases for each electrode correspond to the tri-dimensional “original”. Unit is realized as the PC programmable device, and is successfully used in ECG system tests.

 

Biomaterials and biomechabnics

 

 

BB1

ENHANCED OSTEOCONDUCTIVITY OF HYDROXYAPATITE CERAMICS INDUCED BY PROTON TRANSPORT POLARIZATION CHARGES

 

Satoshi Nakamura, Takayuki Kobayashi, Kimihiro Yamashita

 

Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University,
nakamura.bcr@tmd.ac.jp, 2-3-10 Kanda-Surugadai, Chiyoda, Tokyo 101-0062 Japan

 

Large surface charges were demonstrated to be inducible on hydroxyapatite ceramics by proton transport polarization based on thermally stimulated depolarization measurements.  The polarization of hydroxyapatite was attributed to the migration of protons in the columnar OH channels with a micrometer-order distance.  The charged surfaces of the hydroxyapatite ceramics promoted bone reconstructions in wide defects of canine bones at 7days after the implantation, whereas the processes varied according to the charge polarity.  The enhanced osteoconductions were ascribed to the cooperative reaction of the surface bioactivity of hydroxyapatite and large surface charge induced by the electrical polarization.

 

BB2

BIOFERROELECTRICITY AND BIOMEDICINE: NEW RESULTS AND APPROACHES

 

Vladimir Bystrov, Natalie Bystrova, G. Ovtchinnikova, Yu. Pirogov,

 

Institute of Mathematical Problems of Biology Russian Academy of Sciences, Pushchino, 142290, Moscow region, Russia, Email: Bystrov@impb.psn.ru

 

Experimental results and theoretical approaches in the bioferroelectricity are discussed. The predicted Ferroelectric and Liquid-Crystal-Like Ferroelectric properties of a biological membrane have been experimentally observed in bacteriorhodopsin containing purple membrane films. Experiments confirm the ferroelectric liquid crystal nature of the biomembrane’s ion channels. Bioferroelectric properties of biological objects had developed to the biomedical applications: (i) the nonlinear response on the weak actions (irradiation, external fields etc.) in the vicinity of the critical (bifurcation) point characterized biological object on various levels as on molecular, cell as on the whole organism level; (ii) diagnostic biomedical probe is development of a bone piezoelectricity

BB 3

CONDUCTIVE AND MECHANICAL PROPERTIES OF DNA ARRAYS  

 

Donats Erts1, Boris Polyakov1, Eimer Tuite2

 

1Institute of Chemical Physics, University of Latvia, LV-1586 Riga, Latvia. E-mail: erts@kfi.lu.lv, 2Department of Chemistry, University of Newcastle, Newcastle upon Tyne NE1 7RU, UK

 

Spatially distributed DNA oligomer arrays on Au(111) surfaces were created by self-assembly of monolayers of alkanethiol-conjugated DNA and mercaptohexanol. Tapping mode atomic force microscope (AFM) was used to visualize the DNA distribution on the surface and to study the mechanical properties of individual molecules. It was found that DNA molecules extend approximately vertically upward from the surface. To measure conductance through individual DNA molecules with the conductive AFM, the curves of force and current vs. displacement were obtained. To attain correct interpretation of the experimental results, all types of force interactions between the tip and the surface were analyzed.

 

BB 4

SKULL FRACTURE BIOMECHANICS

 

C. Van Lierde1, B. Depreitere2, J. Vander Sloten1, R. Van Audekercke1, G. Van der Perre1, J. Goffin2

1Division of Biomechanics and Engineering Design, K.U.Leuven, Belgium, e-mail: Carl.VanLierde@mech.kuleuven.ac.be; 2Division of Experimental Neurosurgery and Neuroanatomy, K.U.Leuven, Belgium, e-mail: bart.depreitere@uz.kuleuven.ac.be

 

An investigation was performed to determine the energy necessary to induce skull fracture by means of dynamic external loading, at two rates.  Correlations with skull specific geometrical characteristics and material properties were established using CT-scan data. The study involved developing a dedicated experimental set-up for impacting different sites on the skull and covers measurement results for over 70 specimens.  Preliminary analysis -for frontal impacts- showed the fracture force to vary significantly (p=0.045) between both loading rates, while the absorbed energy was not significantly changed (p=0.88).  Similar trends were seen for temporal, occipital and parietal impacts, though further evaluation is necessary.

 

BB 5

Influence of ULTRAVIOLET, x-ray and electron radiation on chemical and mechanical properties of the bone

 

Tatyana Bogucharska1, Yuri Dekhtyar1, Andreas Heilmann2, Hans-Joachim Hein3, Wigand Hübner4, Sergejs Nazarovs1.

 

1BIMI, Riga Technical University, 1, Kalku str., Riga Latvia, LV-1058, 4 Dep. of Chemistry, MLU Halle-Wittenberg,  3  RG Biomechanics & Structure Research, Dep. of Ortopaedics, Martin-Luther-Universität Halle-Wittenberg, Str. der OdF 4, D-06097, Halle, Gremany, 2 Fraunhofer Institut fuer Werkstoffmechanik, Heideallee 19, D-06120 Halle/S.

 

The alterations in mechanical and chemical properties of the bone, caused by electron, ultraviolet and x-ray radiation were explored. Both electron and x-ray photons had the energy 30 keV.  Scanning acoustic microscopy was applied to detect mechanical (elastic) features. Infrared spectroscopy was in use to recognize reconstruction of chemical couples. The x-ray and ultraviolet radiation resulted both chemical and mechanical peculiarities of the bone. Destruction of the `interface coupling organic and mineral phases was observed. The exited Ca2+ ion bonds became the main source reconstruct the interface. The electron exposure did not provide effects.

 

BB 6

THE INFLUENCE OF IONIZING RADIATION ON THE AMINOACID COMPOSITION OF COLLAGEN

 

Leszek Kubisz, Feliks Jaroszyk

 

Department of Biophysics, Karol Marcinkowski University of Medical Sciences in Poznan, Poland, 61-701 Poznan, Fredry 10, kubisz@main.amu.edu.pl

 

The aim of this work was to compare the amino acid composition of the gamma-irradiated collagen of tendon with the collagen of bone. The analysis of amino acid composition was carried out using the Hirs, Stein and Moore methods by means of automatic analyser. Irradiation with the dose of 50 kGy decreased the total amount of protein. Both the increase and the decrease of the amino acids constituting the collagen content were observed. This depended on the presence of hydroxyapatite (HAP). For glutamic acid and hydroxyproline postradiative changes, because independent on HAP.

 

bb 7

Physical properties of the human bones related to different centuries

 

Andris Actin, Yuri Dehtyar, Hans-Joachim Hein3, Wigand Hübner4, Vladimir Noskov1 , Juris Rauzins, Janis Vetra 2., . Vineta Zemite1,

 

1 - Riga Technical University, BIM Institute, 1 Kalku St., Riga, LV - 1658; Latvia;

2 - Medical Academy of Latvia (Riga Stradins University), 16 Dzirciema St., Riga, LV - 1007, Latvia;4 Dep. of Chemistry, MLU Halle-Wittenberg,  3  RG Biomechanics & Structure Research, Dep. of Ortopaedics, Martin-Luther-Universität Halle-Wittenberg, Str. der OdF 4, D-06097, Halle, Gremany,

 

The main purpose of the present research is to search for physical methods on the best characterisation of structural properties of the human bones related to XIII-XX century range. The morphology measurements were reached at the micro (nano) and macro scales. In parallel, order of the structure, electronic and optical peculiarities were measured using X-ray diffraction photothermostimulated exoelectron emission (EE) and infrared absorption spectroscopy.

The achieved results demonstrated that the most sensitive technology to characterise relation of the bones to different centuries is EE.

 

BB 8

Measurement of skin electric conductance and capacitance after visual stimulation

 

Dariusz Wůodarczyk, Ewa Marzec

 

Department of Biophysics, Karol Marcinkowski University of  Medical Sciences in Poznań, Fredry 10, 61-701 Poznań, Poland, e-mail: wlodarda@main.amu.edu.pl

 

The aim of the studies reported was to compare the skin electric conductance and capacitance in the control group before and after the visual stimulation. The experiments were carried out using alternating current at frequencies from 100 Hz to 100 kHz applied with the help of two electrodes. The electrodes were made of Ag/AgCl and were applied on the hand. The measurements were performed before and after the stimulation. The electric conductance and capacitance of skin in volunteers after stimulation are on average higher by 30% and 18%, respectively, when compared to the results obtained for the this group before.

 

bb 9

Application of Porous Silicon as a Biosensor for Enzymes

 

Prajakta Chaudhari1, Anisha Gokarna1, Manjusha Kulkarni2, N. Karve2 , S.V.Bhoraskar1

 

 1Department of Physics, University of Pune, India; 2Department of Chemistry, University of Pune, India

 

A biopolymer which has enzyme immobilized in porous silicon (PS) was supported, so PS provides an electric and optoelectronic integration for the biological systems. For this, urease (E.C.3.5.1.5) was used. Photoluminescence studies were also carried out for: (i) Enzymes incorporated into biopolymer which is then deposited into porous silicon, (ii) Enzyme alone deposited into porous silicon. The photoluminescence spectrum shows change in the intensity for immobilization. Similar experiments were carried out by changing the porosity of the silicon for improvising the extent of immobilization. The porous silicon can be used as biosensors for detecting the level of enzymes.

 

BBP 1

Studies of the thermal properties of horn keratin by dielectric spectroscopy, thermogravimetric analysis and differential thermal analysis

 

Ewa Marzec, Piotr Piskunowicz, Feliks Jaroszyk

 

Department of Biophysics, Karol Marcinkowski University of  Medical Sciences in Poznań, Fredry 10, 61-701 Poznań, Poland, e-mail: ewaklcde@main.amu.edu.pl

 

The thermal properties of horn keratin have been studied by dielectric spectroscopy in the frequency range 101-105 Hz, thermogravimetric analysis (TGA) and differential thermal analysis (DTA). Measurements of non-irradiated and g-irradiated keratin with doses 5, 50 kGy were performed at temperatures from 22 to 260°C.The results revealed the occurrence of phase transitions related to release of loosely bound water and bound water up to 200oC and the denaturation of the crystalline structure above this temperature. The influence of g-irradiation on the thermal behavior of keratin is significant only in the temperature range of denaturation. The decrease in the temperature of denaturation would suggest that g-irradiation initiates main-chain degradation.

 

BBP 2

RELATIVE VISCOSITY OF THE DISSOLVED IRRADIATED BONE

 

Edward Pankowski, Leszek Kubisz and Feliks Jaroszyk

 

Department of Biophysics, Karol Marcinkowski University of Medical Sciences in Poznan,  Poland, 61-701 Poznan, Fredry 10, kubisz@main.amu.edu.pl

 

 

The bone exposed to the doses higher than 10 kGy is water-soluble. The degree of solubility depends on the duration of the process, dose and temperature of the process. The highest dissolving rate was observed during the first three hours. The aim of this work was to study the relative viscosity as the measure of the radiolytic damage of the bone. The relative viscosity increased rapidly at the temperature of 308 K. The local maximum was observed at the temperature of 313 K. The measured changes in viscosity were in the range of 1.000 Ź1.025.

 

BBP3

synergetical behaviour of the bone structural properties under ultraviolet radiation 

 

Yuri Dekhtyar, Alexei Katashev

 

Biomedical Engineering and Microtechnologies Institute, Riga Technical University, 1 Kalku str, Riga LV-1658, Latvia, dekhtyar@latnet.lv

 

The research was targeted to explore behavior of a bone (bovine) structure resulted by ultraviolet radiation. To find structural alterations exoelectron emission spectroscopy was applied. The experiment demonstrated wave –like behavior of the radiation induced imperfection concentration (IC) on delivered dose. To explain such a phenomenon IC was considered in the frames of the formal annealing kinetic approach. Interaction of two kinds of imperfections placed at both the mineral-organic interface and mineral phase was taken into account. The theoretical calculations became in agreement with experimental results.

 

bbp 4

X-RAY DIFFRACTION ON THE BONE TISSUES

 

Andris Actinsh2; Yuri Dekhtyar1 , Yuris Rauziňsh1;

 

1Department of biomedical engineering and microtechnologies, Riga Techical University, Riga, Latvia; 2Department of chemistry, Latvian States university, Riga, Latvia

 

Abstract. X-ray diffraction was applied to characterize structural properties of the bone mineral phase in dependence on its concentration. The detected maximums were identified as delivered by the pure hydroxyl apatite micro crystals. This evidenced that the latter became the main component of the mineral phase. Chemical etching targeted to escape the minerals was used to simulate decreasing of the hydroxyl apatite volume. The diffraction maximum height was affected by etching. The correlation between duration of chemical treatment and the 2d to 1st main maximum ratio was found.

 

BBP 5

Detection of optically induced electron transitions in bone

 

Yuri Dekhtyar1, Aleksejs Solovjovs1, Irena Egerta2, Vera Grigorjeva2

 

1BIMI, Riga Technical University, 1 Kalku str., Riga, LV-1658, Latvia, e-mail: dekhtyar@latnet.lv, aleksejs.solovjovs@vza.gov.lv, 2State Agency of Medicines of the Republic of Latvia, 15 Jersikas str., Riga, LV-1005, Latvia,e-mail: irena.egerta@vza.gov.lv

 

Bone material absorption of light was measured in the range 250-850nm range by means of Varian-100 spectrophotometer. In addition, optically excited electron transitions via the energy gap were detected. For this the specimens were irradiated by infrared photons alongside with optical absorption spectra measurements. The spectra peculiarities were discovered at ~850-825 nm and ~440 nm. The results provide the evidence that optically induced electron transition in bone could be detected by the above technique.

 

BBP 6

BLOOD RHEOGRAMS MADE ON PATIENTS AFTER MYOCARDIAL INFARCTION

Anna Marcinkowska-Gapinska1, Feliks Jaroszyk2, Leszek Kubisz2

 

1Deparmtent of Neurology Karol Marcinkowski University of Medical Sciences in Poznan, Poland,  60-355, 2 Poznan, Przybyszewskiego 49, Department of Biophysics, Karol Marcinkowski University of Medical Sciences in Poznan,  Poland, 61-701 Poznan, Fredry 10, kubisz@main.amu.edu.pl

 

Blood is a non-Newtonian, viscoelastic fluid. The aim of this work was to study the influence of antithrombotic substances on the blood viscoelastic properties. The apparent viscosity of blood was measured using the rotational viscometer. Blood samples were collected from patients treated with the acetylsalicylic acid  (group A), with the acenokumarin (group B) and from the control group  (C). Measurements were performed at the temperature of 298 and 310 K and for the shearing range of (0.01-100)s-1. Depending of the group of patients (A, B or C) rheograms and apparent viscosity-temperature relationships were different.

 

BBP 7

IMAGE CYTOMETRY ALGORITHM FOR MALE INFERTILITY:TEST WITH TOLUIDINE BLUE ON SPERM SMEARS

 

Juris Erenpreiss1,2, Talivaldis Freivalds3, Maija Slaidina1, Jelena Butikova1, Jekaterina Erenpreisa1

 

1University of Latvia, Biomedicine Research and Studies Centre, Ratsupites 1,Riga, e-mail: cancer@latent.lv; 2Family and Sexual Health Centre, Saharova 16, Riga, e-mail:

family.center@latnet.lv; 3 University of Latvia, Institute of Experimental and Clinical Medicine, Riga.

 

Sperm DNA integrity is of a paramount importance in prognosis of fertility.

We attempted to apply image cytometry for sperm test with toluidine blue(TB). On sperm smears TB-test was carried out followed by CCD image cytometry and discrimination of sperm cell nuclei by four colours corresponding different DNA integrity. Image cytometry was verified by spectrocytophotometry and cytochemical probes. Sperm cell CCD discrimination was supported by clinical assessment of sperm quality and fertility. We have shown that TB-test using the elaborated image cytometry algorithm is able to predict fertility by the parameter of sperm cell DNA integrity consistent with literature.

 

BBP 8

PREPARATION AND PROPERTIES OF HYDROXYAPATITE OBTAINED FROM SOLUTIONS THROUGH SPRAY-DRYING TECHNIQUE

 

Liene Actiňa, Çriks Palčevskis, Antonija Dindune

 

Institute of Inorganic Chemistry, Riga Technical University, Miera 34, Salaspils LV-2169, tonija@nki.lv

 

In the present work high dispersed and granulated stoichiometric hydroxyapatite (HA) powders (specific area ~50-80 m2/g) has been obtained from suspensions by using spray-drying technique. Formed laboratory equipment allows preparing ~400-500 g HA powders at once. The effects of varying synthesis conditions on stoichiometry and morphology of the HA powder are reported. HA powders were chemically and physically characterised using X-ray diffraction, DTA, electron microscopy and specific surface area analysis. In order to obtain high density HA (and composite) ceramics, pellets of HA (and with ZrO2, Al2O3 etc.) have been manufactured by pressing and thermal treatments have been investigated.

 

BBP 9

NON-LINEAR DYNAMIC MODELS OF TRASITIONAL PROCESSES IN THE BIOLOGICAL AND FERROELECTRC-LIKE SYSTEMS 

 

Vladimir Bystrov1, Tatyana Tazieva, Alla Sapronova, Natalia Bystrova2

 

1Institute of Mathematical problems of Biology RAS, bystrov@impb.psn.ru , 2Institute of Theoretical and Experimental Biophysics RAS, nkbys@mail.ru

 

Dynamics and features of various complex systems at the transients (phase transitions, the switching processes, transition from one regulation level on the another) mathematically are described by the similar nonlinear equations. The solutions of the nonlinear equations and features of the basic characteristics describing behavior of system in the transition vicinity of the ferroelectric and them similar systems at the change of various external influences are investigated. The received results are applicable both to ferroelectric and to biological systems.

 

BBP10

THE INFLUENCE OF THE ACETLSALYCILIC ACID  AND ACENOKUMAROL ON THE COMPLEX VISCOSITY  OF BLOOD

 

Anna Marcinkowska-Gapinska1, Feliks Jaroszyk2 and Leszek Kubisz2

 

1Deparmtent of Neurology Karol Marcinkowski University of Medical Sciences in Poznan, Poland,  60-355, 2Department of Biophysics, Karol Marcinkowski University of Medical Sciences in Poznan, Poznan, Przybyszewskiego 49, Poland, 61-701 Poznan, Fredry 10, kubisz@main.amu.edu.pl

 

Viscosity of blood plasma and complex viscosity of blood measurements were performed using the Contravens LS –40 rheometer, at 298 K and 310 K, for the frequency of oscillation of 0.5 Hz and  the shearing rate of  0.01-100 s-1. Blood samples were collected from patients treated with the acetylsalicylic acid  (group A), with the acenokumarin (group B) and from the control group  (C).  The complex viscosity of blood of the group A shown no differences with the control (C). For the group B, the elastic component of the complex viscosity shown higher values at the low shearing rate.

 

BBP11

Investigation of capillary blood flow in masseteric muscles with Laser Doppler flowmetry.

 

Mara Apine

 

Riga Stradina university/Medical Academy of Latvia, Dzirciema Str. 20, Riga LV-1007, Latvia, E-mail: maralaima@hotmail.com

 

 

Permanent pain syndrome and functional disturbances in stomathognathic system are typically for craniomandibular disorders (KMD). One of major mechanism that may explain myalgia is decreased intramuscular blood flow (IMBF), caused by mechanical compression of blood vessels, due to sustained muscle contraction. The aim of this study: observe microcirculation in relation with masseteric muscle pain by KMD patients (10 female, 5 male 19-29 years, as well as 10 female and 5 male 19-29 years old) with arthritis IIIb cause group. The correlation of microcirculation dynamics in mandibular kinetics and muscle symptoms was discovered.

 

 

Field Instrumentation and measurements

 

IM 1

POROGRAMMABLE DATA ACQUISITION AND CONTROL SYSTEM 

 

Juris Lauznis, Gunars Balodis

 

JSC “AMERILAT”, lauznis@amerilat.lv , gunars@amerilat.lv .

 

Reprogramming of Data Acquisition and Control System (DACS) in most cases is very complicated. Presented DACS consists of 12-bit, 8-channel ADC, 8-bit, 2-channel DAC and 4 digital I/O lines controlled by Parallax Basic Stamp BS2p chip, connected to the RS-232 or USB port of PC. Advantage of this solution is possibility of easy and fast reprogramming of DACS algorithms using PBASIC language directly from connected PC. Primary unit was designed to develop new temperature measurement and control modules for medical equipment, but can be also used in scientific experiments and process control.

 

im 2

Quantitivity analisys of ocular fluorescense as measured by two fluorometers after oral and intravenous administration of sodium fluorescein

 

Jose Domirques1, Joao Figueira2, Fausto Carvalheira2, Paulo Ricardo, Antonio Barata1, Carlos Correia1, Jose Cunha-Vaz2     

 

1Physics Department of University of Coimbra, 2 Biomedical Institute for Research on Light and Image Coimbra, Portugal; e-mail: jpd@imagemibili.uc.pt

 

Ocular Fluorometry is a method with recognized utility in Blood-Ocular Barries evaluation namely, the assessment of the relation between their leakage and duration of diabetes disease and degree of diabetic retinopathy. Fluorometric measurements with the Fluorotron Master (FM) were compared with a new ocular fluorometer we developed (PAF). Both endo venous and oral examination presented no statistically important deviations between FM and PAF results. PAF showed itself efficient in vivo ocular anterior segment fluorometry (reproducibility and accuracy). Oral fluorescein administration a safer method for patients, proved to be compatible with measurable levels of fluorescence both in plasma and the eye.

 

IM 3

Luminescence materials with high biological activity
on the base of azaaromatic compounds

 

O.N. Chupakhin, V.N. Charushin, V.L. Rusinov, G.L. Rusinov, D.V. Raikov, V.L. Petrov, B.V. Shulgin, N.N. Mochulskaya, A.A. Andreiko, I.S. Kovalev, L.I. Tarkhov, S.G. Mikhailov,

 

Urals State Technical University, 19 Mira Street, Ekaterinburg, 620002, Russia,
Phone: +007-3432-75-4876, Fax: +007-3432-74-3884, E-mail: bvs@dpt.ustu.ru

 

The photo- and radioluminescence of some new organic materials (with high biological activity) were investigated. To elucidate the luminescence nature, quantum compounds has been carried out. The new class of fast organical scintillators on the basis of nitrogen-containing heterocycles has been proposed. These scintillators can be used in conjunction with the ordinary photomultipliers with multyalkaline photocathodes and with PIN – photodiodes for compact detectors. The new scintillators can be used for detection and visualization of a-, b-, g-, X-ray radiation and neutrons, with heightened efficiency. The nature of high biological activity some azaaromatic compounds is discussed in comparison with luminescence activity.

 

IM 4

A portable photoplethysmography device for cardio-vascular assessment

 

Janis Spigulis*, Maris Ozols, Renars Erts, Karlis Prieditis

 

University of Latvia, Physics Department and IAPS, Raina Blvd. 19, Riga, LV-1586, Latvia, E-mail janispi@latnet.lv

 

A hand-held prototype device for detection and processing of the tissue-remitted optical signals is developed and tested. The photopethysmography (PPG) sensing principle is applied to follow the expansion and shrinking of blood vessels during the cardiac cycle. Parameters associated with PPG signal sequences and the mean single-period PPG (or SPPPG) signal shapes are used as main indicators of the person’s cardio-vascular condition; the whole procedure takes about 2 minutes.

imp 1

Measurement Accuracy for BONE Otical Absorption

 

Nina Mironova-Ulmane2, Irina Pavlenko1, Andrei Pavlenko1

 

1BIM Institute, Riga Technical University, 1 Kalku St, LV-1658 Riga, Latvia dekhtayr@latnet.lv , 2 Solid State Physics Institute, University of Latvia Miera str.31 LV-2961 Salaspils Latvia ulman@latnet.lv.

 

An optical properties of the bone, which is a complicated organic material requires detailed planning of experiments and equipment adjustment. Accuracy of measurement is considered to be the most important factor. The present work is targeted to verify accuracy of optical density measurement and optimize procedure to test the bone by means MORPHOQUANT optical analyzer.

 

imp 2

Application of Hilbert Spectral Analysis to Transient Evoked Otoacoustic Emissions Data

 

Aldis Balodis1 , Sandra Kuske2 Pçteris Skorovs1, Janis Sokolovs2

1Institute of Biomedical Engineering and Microtechnologies,

Riga Technical University, Riga, Latvia, 2Departament of ENT, Medical Academy of Latvia, Riga, Latvia

 

The aim of this study is to evaluate the Time-Frequency properties of Transiently Evoked Otoacoustic Emissions (TEOAEs).

Hilbert Spectrum Analysis method was applied to obtain Time-Frequency representations from neonatal and children TEOAEs. It is argued that Hilbert Spectrum Analysis in comparison with other Time-Frequency methods is more appropriate, because of transient and non-stationary nature of TEOAEs.

Results indicate that Hilbert Spectrum Analysis gives the superior resolution and most detailed information from TEOAEs.

 

 

Field Materials for Micro and Nano technologies

 

MM 1

PROPERTIES OF SILICON NANOWIRES

 

Donats Erts1, Borys Polyakov1, J. D. Holmes2, H. Olin3

 

1Institute of Chemical Physics, University of Latvia, LV-1586 Riga, Latvia. E-mail: erts@kfi.lu.lv; 2Department of Chemistry, University College Cork, Ireland; 3Physics and Engineering Physics, Chalmers University of Technology, SE-412 96 Göteborg, Sweden

 

Nanowires are expected to play an important role in future electronic, optical devices, and in nanoelectromechanical systems We report on silicon nanowires grown on Au. Si nanowires were several micrometers long and 40-90 nm wide. To measure the electrical or mechanical properties of nanowires we used an in-situ probing technique, which is a combination of the scanning tunneling microscope and the transmission electron microscope. The current-voltage curves showed linear as well as highly non-linear behavior. The mechanics were studied by electrostatic deflection, van der Waals interactions, and adhesion area measurements. The force constants of the nanowire were between 0.005-0.1 N/m.

 

MM 2

X-RAY EMISSION STUDY OF NANOCRYSTALLINE TiO2 

 

Dmitry Zatsepin1, Vladimir Cherkashenko1, Ernst Kurmaev1, Vladimir Ivanov2, Seif  Cholakh2

 

1 Institute of Metal Physics, Russian Academy of Sciences – Ural Division, 620219 Yekaterinburg, Russia, d_zatsepin@ifmlrs.uran.ru, 2Institute of electrophysics, 620016, Yekaterinburg, Russia, ivanov@iep.uran.ru

 

 The electronic structure of nanocrystalline TiO2 powder (22% of rutile phase with 52 nm particles size and 78% of anataz phase with 55 nm particle size) has been studied using X-ray emission spectroscopy (Ti La-b, O Ka). These spectra originate due to Ti 3d4s ® Ti 2p3/2,1/2 and O 2p ® O 1s electron transitions and reflect the distribution of Ti 3d and O 2p partial densities of states in the valence band. The X-ray emission spectra of nano TiO2 were compared with that for reference TiO2 sample. It was found that there is no significant difference in XES Ti La-b for nano and reference sample whereas the XES O Ka transforms significantly. The main difference in oxygen Ka emission band results in widening of the low-energy sub band that reflects the hybridised Ti 3d – O 2p bonding states.   Taking into account the results obtained we can conclude that the main difference in the electronic structure of 50 nm TiO2 and reference TiO2 is the hybridisation degree of 3d metal2p ligand electronic states.  Also the analysis of XES Ti  La-b  shows that  the titanium ions in 50 nm TiO2 keep their valence states as 4+.

MM 3

Physical simulation of a Czochralski process of silicon single crystal growth

 

Alexander Pedcenko RTU, BIMI

 

The method of physical simulation of Czochralski silicon single crystal growth (CZ) is presented. The experimental facility allows to investigate the hydrodynamics and heat transfer in CZ for the basic criteria of the simulation process (Re, Gr) being equal to the actual values of these criteria for the silicon single crystal growth process, implementing the real boundary conditions for the heat flows on the walls and bottom of the crucible as well as on the melt free surface. The maximum approximation to the actual process of large diameter silicon single crystal growth is the main achievement of the presented method. The report discusses the results of the hydrodynamics and heat transfer simulation of a 150 mm silicon crystal pulled from 500 mm crucible.

 

MM 4

Evaluation of the surface defectness for optimisation of the manufacturing technology

G. Sagalovich

 

Institute of Biomedical engineering and Microtechnology, Riga Technical University, 1 Kalku St, Riga LV-1658, Latvia;

 

Indices of reliability of details, identical both by shape and material, are widely scattered. Details interghangeability indices should account for physical / chemical properties and their variations due to environmental and technological factors, that may be studied using structural-sensitive methods, such as exoelectron emission (EEE) defectoscopy. The experiment-measured input both by dislocations has been implemented by means of plastic deformation, and point-type defects. Boundary conditions of such an experiment have been taken into account, beyond which the experiment errors may surpass the error of EEE record and could result a number of undesirable side effects.

 

 

 

Field Education

 

E 1

EDUCATION AND TRAINING IN MEDICAL PHYSICS 

 

Franco Milano

 

Dept. of Clinical Physiopathology  University of Florence

 

A foundation in medical physics is important for the practice of a physicist in particular when ionizing radiations are used either in diagnosis or in therapy. In many Countries scientific organizations and legislative national Bodies have constructed curricula for the medical physicist. The EC Directives concerning basic safety standards and medical exposures have given statutory requirement for physicists to be involved in the medical use of ionising radiations. An outline of the medical physicist’s duties, curricula and training is presented as a basis to introduce the curricula in a specific national scheme in agreement with the existing legislation constraints.

 

E 2

BIOMEDICAL ENGINEERING: CONCEPTION OF TWO DIPLOMAS

 

Borys Samotokin1, Wolfgang Shuler 2.

 

1 Zhytomyr Institute of Engineering and Technology (Ukraine); bbs@ziet.zhitomir.ua; 2Mittweida University of Applied Sciences (Germany); email: sbchem@aol.com

The processes of integration in Europe require overcoming of national frames of higher education. In present report, the concept of two diplomas on Clinical Engineering specialty is discussed on example of collaboration of Ukrainian and German universities and the scheme: ZIET Engineer + MUAS Diploma Engineer, or ZIET Master + MUAS Master is proposed. The agreement protocol among cooperating Universities should foresee mutual recognition of credits, involvement of most qualified lecturers in the process of students training, unification of the requirements for diploma projects. International program may be enlarged, for example, by participation of Riga Technical University (Latvia) in it.

 

E 3

TRAINING OF THE BIOMEDICAL LABORATORY TECHNICIANS IN LATVIA

 

Silvija Daudze, Maija Kurmina

 

P. Stradins Medical School, e-mail: st-skola@apollo.lv

 

The profession of the biomedical laboratory technician can be mastered only in P. Stradins Medical School, founded in 1939. Almost 1000 people has been trained during 60 years. Length of the studies is 2 years. School have entered into agreements with many foreign colleges and universities in Sweden, Denmark, Finland, Germany, Spain, UK, Lithuania etc. Since 1999 the school has been organizing postgraduate courses. Education delivered by the P. Stradins Medical School to biomedical laboratory technicians provides a good basement to enter continuing studies at Biomedical engineering and physics field delivered at the RTU.