The application of ultrasound in neuroendoscopic procedures: first results with the new tool »NECUP-2« [Upotreba ultrazvuka u neuroendoskopskim procedurama: prvi rezultati s novim uređajem »NECUP-2«]

In this paper, our experience with originally constructed Neurosurgical Endoscopic Contact Ultrasound Probe »NECUP-2« in neuroendoscopy is reported. Between June 1997 and June 2007, 132 neuroendoscopic procedures have been performed: 102 endoscopic thrid ventriculostomies (ETV), 15 arachnoid cysts and 5 intraventricular tumours operations. The »NECUP-2« was applied effectively in all cases in which blunt perforation was not possible: 38/102 ETV, 10/10 septostomies, 15/15 arachnoid cysts. In five cases of intraventricular tumours, neuroendoscopic procedure was combined with open microsurgery for tumour removal with preservation of vascular structures. There were no »NECUP-2« related complications. Of postoperative complications, we had liquorrhea (9 patients), and symptoms of meningitis (6 patients). In the follow-up period (6 months to 6 years), we had a patency rate of 80% (50/63 patients). All patients improved in clinical status. According to the first results, it seems that ultrasonic contact probe NECUP-2 presents a new device in neurosurgical armamentarium that can be used in various fields of neurosurgery. With minimal and controlled lesion that is produced at the tip of the probe, it can be used in highly demanding operations such as third ventriculostomy and tumour resection

Cardiovascular Drugs Consumption - Comparison between Two Croatian Regions, City of Zagreb and Lika-Senj County

The aim of this paper is to determine the differences in the outpatient consumption of cardiovascular drugs between Croatian regions: the City of Zagreb and Lika-Senj County. The data on the number of packages and the purchase price for each drug have been obtained from all pharmacies in Lika-Senj County and all pharmacies in the City of Zagreb. Defined daily doses/1000 inhabitants/day (DDD/1000/day) was calculated for every drug in accordance with its code name and Anatomical Therapeutic Chemical/Defined Daily Dose (ATC/DDD) index of the World Health Organization (WHO) for 2007. For drug combinations without defined daily doses, equivalent doses (ED) were used. The quality of drug prescribing within the group of cardiovascular drugs was assessed using the Drug Utilization (DU90%) method and the adherence of the DU90% segment to the guidelines for prescribing individual drug groups. The statistical significance of differences in results between the City of Zagreb and Lika-Senj County was tested using the chi-square test at the level of statistical significance p<0.05. The comparison of the share of the five most often prescribed drug groups in Lika-Senj County has shown statistically significant differences when compared to the City of Zagreb (χ2=28.93, df=4, p<0.001). The total outpatient consumption of cardiovascular drugs in the City of Zagreb and Lika-Senj County differs significantly. The consumption, quality of prescribing drugs and cost/DDD in the City of Zagreb is higher than in Lika-Senj County; in the City of Zagreb, newer and more expensive drugs are prescribed to a higher extent

Karcinom bubrežnog sabirnog kanala: prikaz triju slučajeva

Collecting duct carcinoma or Bellini duct carcinoma is a highly malignant neoplasm that arises from the collecting duct epithelium of the kidney and accounts for approximately 1% of renal neoplasms. Collecting duct carcinoma generally pursues a more aggressive course than conventional renal cell carcinoma. Metastases to regional lymph nodes, bone, adrenal glands, lung, skin and meninges have been reported. During the 1998-2000 period, 161 patients underwent nephrectomy due to renal cell carcinoma at our hospital. The patients’ age ranged from 24 to 90 (mean 59.5) years. There were 50 female and 111 male patients. Collecting duct carcinoma was diagnosed in three (1.9%) male patients aged 79, 66 and 67 (mean age 71.0) years. The patients presented with hematuria associated with fever, weight loss, pain and palpable abdominal mass. On gross examination, the tumors were located in the medulla of the kidney and extended into the cortex and adjacent adipose tissue. Histologically, the tumors showed tubulopapillary, tubular or solid areas. Immunohistochemically, positive staining with cytokeratin, EMA and Ulex Europaeus agglutinin was observed. All patients had regional lymph node metastases, and two of them died within one month from surgery. The third patient was alive and without signs of recurrence six months from presentation.Karcinom sabirnog kanala ili karcinom Bellinijeva kanala je visoko maligna neoplazma koja nastaje iz epitela bubrežnoga sabirnog kanala i čini otprilike 1% bubrežnih neoplazma. Karcinom sabirnoga kanala uglavnom ima agresivniji tijek od konvencionalnog karcinoma bubrežnih stanica. Opisane su metastaze u regionalne limfne čvorove, kosti, nadbubrežne žlijezde, pluća, kožu i meninge. U razdoblju od 1998. do 2000. godine u našoj je bolnici 161 bolesnik podvrgnut nefrektomiji zbog karcinoma bubrežnih stanica. Bolesnici su bili u dobi od 24 do 90 godina (srednja dob 59,5 godina), a bilo je 50 žena i 111 muškaraca. Karcinom sabirnog kanala dijagnosticiran je u trojice (1,9%) muških bolesnika u dobi od 79, 66 i 67 godina (srednja dob 71,0 godina). Bolesnici su došli s hematurijom udruženom s groznicom, gubitkom težine, bolovima i opipljivom masom u trbušnoj šupljini. Makroskopskim pregledom su tumori locirani u bubrežnoj meduli, a protezali su se u koru i obližnje masno tkivo. Histološki su tumori pokazivali tubulopapilarna, tubularna ili kruta područja. Imunohistokemijski je zabilježeno pozitivno bojenje citokeratinom, EMA i Ulex Europaeus aglutininom. Svi su bolesnici imali metastaze regionalnih limfnih čvorova, a dvojica su umrla kroz mjesec dana nakon operacije. Treći je bolesnik bio živ i bez znakova ponovljene bolesti šest mjeseci nakon dolaska u bolnicu

Model zdravstveno edukativne radionice

Ponukani sve većim zahtjevima i potrebama naših građana i pacijenata (intolerancija na hranu, zdravstveni status, eliminacijska dijeta, zamjenske namirnice te drugi novi režim prehrane) pokrenute su zdravstveno-edukativne radionice Centru za preventivnu medicinu u „Zavodu za javno zdravstvo dr. Andrija Štampar“.Cilj radionica je pomoći oko usvajanja novih znanja i iskustava u prehrani vezano uz testove intolerancije na hranu (upoznavanje i uvođenje novih namirnica u prehranu, novi načini pripremanja hrane, razmjene iskustava i receptura...) a ujedno i prevencija debljine i rizičnih čimbenika za nastanak kroničnih nezaraznih bolesti.

Model zdravstveno edukativne radionice

Ponukani sve većim zahtjevima i potrebama naših građana i pacijenata (intolerancija na hranu, zdravstveni status, eliminacijska dijeta, zamjenske namirnice te drugi novi režim prehrane) pokrenute su zdravstveno-edukativne radionice Centru za preventivnu medicinu u „Zavodu za javno zdravstvo dr. Andrija Štampar“.Cilj radionica je pomoći oko usvajanja novih znanja i iskustava u prehrani vezano uz testove intolerancije na hranu (upoznavanje i uvođenje novih namirnica u prehranu, novi načini pripremanja hrane, razmjene iskustava i receptura...) a ujedno i prevencija debljine i rizičnih čimbenika za nastanak kroničnih nezaraznih bolesti.

ProductionAspect of Silver Fir (Abies alba Mill.) Dieback on Example of a few Beech-fir Stands

Problematika koju rad istražuje je sušenje obične jele u bukovo-jelovim šumama s proizvodnog stajališta. Proizvodnjom šumskih drvnih sortimenata jele u sastojinama različitih kategorija zdravstvenog stanja, ostvaruje se sortimentna struktura koja vrlo često značajno odstupa od planirane strukture, a time i od planiranih prihoda proizvodnje. Navedene razlike između planirane i ostvarene proizvodnje, koje su značajne za sastojine u kojima je jela umjereno do izrazito narušenog zdravstvenog stanja, ponajprije promatrajući osutost krošanja, glavna su tema ovoga rada. Područje istraživanja određeno je granicama Uprave šuma Podružnice Delnice, s naglaskom na one gospodarske jedinice, odnosno odjele zahvaćene intenzivnim sušenjem stabala jele. U skladu s tim, te uz stručnu pomoć Ekološkog i Proizvodnog odjela navedene Podružnice, prikupljanje podatka obavljeno je na području gospodarskih jedinica “Brloško” i “Široka Draga”. Osnovna razlika na temelju koje su te jedinice odabrane je u kategoriji općeg zdravstvenog stanja stabala jele. Terensko istraživanje provođeno je u skladu s operativnim proizvodnim planom Podružnice za svaku godinu istraživanja, na način da je odabrano nekoliko odjela/odsjeka predviđenih za prebornu sječu tijekom godine. Na terenu su prikupljani podaci o oborenim jelovim stablima i to osnovne mjerne veličine prsni promjer i ukupna visina stabla, te mjere svakog izrađenog i klasiranog sortimenta iz stabala uzorka. Prikupljeni terenski podaci obrađivani suMicrosoft Excel 2007, te SPSS programom za statističku obradu podataka. Analizom su potvrđene statistički značajne razlike između planirane i ostvarene proizvodnje drvnih sortimenata jele u odjelima sa značajnim sušenjem jele, a dokazane su značajne razlike između proizvodnje istovrsnih sortimentnih klasa pridobivenih iz jelovih sastojina različitih kategorija zdravstvenoga stanja.The research problem, raised by Croatian Forests Ltd., Forest Administration Delnice, is the frequent discrepancy in planned versus realised yields during selecting cutting in fir-beach forests. This discrepancy between planned and realised wood assortments structure and at the same time between revenues, is significant for fir-beach stands affected by fir trees dieback. The result is that performed sylvicultural activities in such disturbed stands, in order to get timber assortments, have questionable cost-effectiveness, and in some cases are fully unprofitable. The key point in process of calculating planned values according to timber assortments are so called “Assortment tables”, empirical models for estimation of timber assortments structure, which are definitely inappropriate for current climatic and disturbed stand conditions. Hence, the aim of this research is to study existing Assortment tables for fir, which are used by the Production department of Forest Administration branch Delnice, in order to satisfy criteria for sufficiently reliable planning in the production of timber assortments. Material and methods. In order to ensure quality and uniformity of research from the be ginning, the detailed plan of field activities was designed and agreed for implementati on with Production department. On the research area in target Forest management un i ts, a few forest compartments were chosen for field data acquisition each year. In each of selected forest compartments it was required to collect data for around 100 marked fir tr ees, which were felled during selecting cutting. Diameter distribution of those hundred tr ees should represent fir diameter distribution of whole compartment. Each of those fir tr ees got measured diameter at breast height, total height, height of the first branch, and all bucked timber assortments. From those data we got volumes (per trees and per timber assortment). Ultimately, assortment structure data were collected from seven forest co mpartments. Each compartment has two dataset, one representing produced timber assortments (done by foresters) versus planned assortment structure (calculated using assortments tables). Concerning research aim, two hypotheses (H1, H2) were constructed. H1 states: If planned and realised timber assortments production from forest compartment significantly affected by fir dieback is compared, than statistically significant differences between planned and realised values according to assortments classes will be confirmed. H2 states: If timber assortments production is compared according to three general health categories of fir stands, than statistically significant differences between same assortment classes will be confirmed. For testing H1, One-way ANOVA was used together with Test of Homogeneity of Variances. Analysed variables are veneer logs volume, sawlogs (1st, 2nd and 3rd class), pulp-wood and firewood, and volume of wood residues (recovered wood). Pulp-wood and firewood are in the same category, because only 14 pieces of firewood were measured in whole sample. Wood residue category refers to timber assortments thicker than 16 cm and left on forest floor because of its uselessness for technical purposes (damaged, decayed). Statistical significance of differences between samples of planned and realised volume according to assortment classes was analysed. Testing homogeneity of variances between these two samples showed in most cases that variances of the same assortment classes’ volumes are not homogenous. Considering this findings, Independent-samples T test was used for analyzing H1. Analog to H1 testing, the same tests were used for H2 analyzing. Forest compartments which were compared represented two of three health categories of fir stands (stands of moderately damaged health condition were missing). Those two compared groups of data were unequal in size, one consisting of data acquired from 5 forest compartments, and another of data acquired from two forest compartments. This research was partially extended with sampling of fallen fir trees to get a clue about insect and pest species which could be one of main factors causing fir dieback. So, in the 2008 woody samples collected from fallen trees in one forest compartment, were analysed in CFRI laboratory. Research area. In wider context, research area represents fir-beach stands of Gorski Kotar region, and narrower area is determined by boundaries of Forest Administration Branch Delnice i.e. forest area affected by intensive fir trees dieback. The stands in focus represent main fir-beach forest community in Gorski Kotar, Abieti-Fagetum illyricum Ht. Research activities on field data acquisition were started in forest management unit “Brloško”. Data about forest compartments included in research are presented in Table 1. Results of research and discussion. Firstly, the results of H1 are presented and discussed. Statistically significant differences between planned and realised volumes were confirmed for veneer assortment, for all forest compartments except one. The results were expected because five of seven compartments are considered as stands of significantly disturbed health condition, where possibility for production of high quality timber assortments from fir trees is minimal. Another fact considerably affects on differences between planned vs realised timber assortment structure is assortments tables, according to which each tree with dbh higher than lowest threshold for veneer class gets certain veneer volume from tree volume. Veneer volume participates in the whole sample of produced timber assortment volume with 0.59 %, and concerning forest compartments from 0.00 % to maximum 3.01 % (see Table 2). T-test results for 1st class saw logs confirmed discrepancies between realised and planned quantities for all forest compartments except compartment no.15 in forest management unit “Brloško” (t value is 0.80). Volume of 1st class saw logs participates in the whole sample of produced timber assortment volume with 5.85 % to 35.95 %, concerning forest compartments. Different from previous, t-test for 2nd class saw logs confirmed discrepancies between realised and planned quantities for three forest compartments, two representing category of good health condition, and one category of worse health condition (table 3). Volume of 2nd class saw logs participates in the whole sample of produced timber assortment volume with 13.93 % to 31.28 %, concerning forest compartments. Testing volume of 3rd class saw logs confirmed discrepancies between realised and planned quantities for four forest compartments (two in category of good health condition, and two in category of worse health). This assortment class after pulp-wood and firewood has the highest share in whole sample volume of assortment classes. Volume of 3rd class saw logs participates in the whole sample of produced timber assortment volume with 16.29 % to 36.90 %, concerning forest compartments. The most frequent timber assortment is pulp-wood and firewood category, leading by number of logs. This fact is in line with disturbed wood quality of standing fir trees which are in process of dieback or completely dead trees in the felling moment. Analysing discrepancies between realised and planned quantities for this assortment category, tests confirmed statistically significant difference for all forest compartments except one. Tested wood volume of the category participates in the whole sample of produced timber assortment volume with 6.38 % to 54.41 %. Recovered wood (i.e. wood residue) assortment is problematic because of its technical inapplicability. This assortment category consisted of small number of pieces, and according to assortment tables each tree gets certain volume of the assortment (so called wood waste). This discrepancy is supported with T-test results confirming significant differences between realised and planned quantities for all forest compartments. Hence, further consideration of the recovered wood assortment was cancelled. Regarding to obtained results, it can be concluded that H1 is accepted because statistically significant differences have been confirmed for majority of tested combinations. Testing H2 by ANOVA and T-test, for each assortment class were confirmed differences between assortment volume variances comparing two health categories of stands (table 4). Other words, the relationship between health categories of fir stands and realised assortment structure has been confirmed. Concerning this, in process of timber assortment production planning more attention on assortments tables should be done (carefully choosing and constructing new ones adapted for different health categories). Conclusions. This project was aimed to give additional contribution in resolving discrepancy between planned and realised timber assortment production from fir-beech stands with different degree of fir trees dieback. The main reason for this discrepancy, especially in case of same health category stands, most probably lays on current assortments tables which were constructed in 90’is and updated a few times mostly on empirical basis. Another reason, but with considerably smaller influence on final production plan than assortment tables is inappropriate tariff selection. Performed statistical tests confirmed significant differences between planned and realised timber assortment quantities in case of veneer. And such results are in strong correlation with worse health condition of the majority ofresearched forest compartments (except the ones in f.m.unit “Široka Draga”). Tests have been confirmed H1 on other timber assortments mostly for 1st and 3rd class of saw logs, pulp-wood and firewood category, and for 2nd class saw logs haven’t. Worse wood quality of fir trees from stands with significant fir dieback resulted in the statistically significant differences between planned and realised values of pulp-wood and firewood assortment volumes. Recovered wood category hasn’t been further analysed because of quite a small sample collected on the field. Testing H2 on realised production data of the same timber assortment types between forest compartments belonging different health category, significant discrepancies in quantities of assortment volumes between two observed health categories have been confirmed. Final recommendation or question to forest Management is “Would it be possible to adjust spatio-temporally the realisation of sanitary selecting cutting in fir-beach forests on yearly basis, in order to minimise timber production costs?

Karcinom bubrežnog sabirnog kanala: prikaz triju slučajeva

Collecting duct carcinoma or Bellini duct carcinoma is a highly malignant neoplasm that arises from the collecting duct epithelium of the kidney and accounts for approximately 1% of renal neoplasms. Collecting duct carcinoma generally pursues a more aggressive course than conventional renal cell carcinoma. Metastases to regional lymph nodes, bone, adrenal glands, lung, skin and meninges have been reported. During the 1998-2000 period, 161 patients underwent nephrectomy due to renal cell carcinoma at our hospital. The patients’ age ranged from 24 to 90 (mean 59.5) years. There were 50 female and 111 male patients. Collecting duct carcinoma was diagnosed in three (1.9%) male patients aged 79, 66 and 67 (mean age 71.0) years. The patients presented with hematuria associated with fever, weight loss, pain and palpable abdominal mass. On gross examination, the tumors were located in the medulla of the kidney and extended into the cortex and adjacent adipose tissue. Histologically, the tumors showed tubulopapillary, tubular or solid areas. Immunohistochemically, positive staining with cytokeratin, EMA and Ulex Europaeus agglutinin was observed. All patients had regional lymph node metastases, and two of them died within one month from surgery. The third patient was alive and without signs of recurrence six months from presentation.Karcinom sabirnog kanala ili karcinom Bellinijeva kanala je visoko maligna neoplazma koja nastaje iz epitela bubrežnoga sabirnog kanala i čini otprilike 1% bubrežnih neoplazma. Karcinom sabirnoga kanala uglavnom ima agresivniji tijek od konvencionalnog karcinoma bubrežnih stanica. Opisane su metastaze u regionalne limfne čvorove, kosti, nadbubrežne žlijezde, pluća, kožu i meninge. U razdoblju od 1998. do 2000. godine u našoj je bolnici 161 bolesnik podvrgnut nefrektomiji zbog karcinoma bubrežnih stanica. Bolesnici su bili u dobi od 24 do 90 godina (srednja dob 59,5 godina), a bilo je 50 žena i 111 muškaraca. Karcinom sabirnog kanala dijagnosticiran je u trojice (1,9%) muških bolesnika u dobi od 79, 66 i 67 godina (srednja dob 71,0 godina). Bolesnici su došli s hematurijom udruženom s groznicom, gubitkom težine, bolovima i opipljivom masom u trbušnoj šupljini. Makroskopskim pregledom su tumori locirani u bubrežnoj meduli, a protezali su se u koru i obližnje masno tkivo. Histološki su tumori pokazivali tubulopapilarna, tubularna ili kruta područja. Imunohistokemijski je zabilježeno pozitivno bojenje citokeratinom, EMA i Ulex Europaeus aglutininom. Svi su bolesnici imali metastaze regionalnih limfnih čvorova, a dvojica su umrla kroz mjesec dana nakon operacije. Treći je bolesnik bio živ i bez znakova ponovljene bolesti šest mjeseci nakon dolaska u bolnicu

Opportunistic screening for colorectal cancer in high-risk patients in family medicine practices in the Republic of Croatia

Colorectal cancer is a malignant neoplasm which has an increasing incidence and represents a global public health problem. The majority of patients are diagnosed after the age of 50, and the risk of developing it over lifetime is 5%. Development of preventive, diagnostic and treatment methods has resulted in a significant reduction in mortality and other negative clinical outcomes. Precisely because of the efficient method of prevention and early detection of this disease, numerous countries, including Croatia, have organized national colorectal cancer screening and monitoring programs. However, these programs are primarily organized for the population with the usual, i.e. average risk of developing colorectal cancer. High-risk groups include persons with endoscopically detected and removed colon polyps, persons surgically treated for colon cancer, persons with a positive family history of colorectal cancer, persons with inflammatory bowel diseases, individuals and families with hereditary disorders or genetic mutations that increase the risk of this disease several fold, persons with acromegaly, and patients who have undergone ureterosigmoidostomy. Recommendations for the detection and monitoring of high-risk groups are often not defined clearly, and some of the existing ones are based mostly on scarce scientific evidence. It is commonly accepted that screening in high-risk groups should start at an earlier age, with shorter intervals between follow-ups. The basic diagnostic method for screening and monitoring in these patient groups is endoscopic monitoring, or colonoscopy. The aim of this review paper is to present the characteristics of the abovementioned risk groups and provide clear screening recommendations

Properties of shortest path bridging protocol in LANs

Najkraći put premošćivanja (SPB) razvijen je kako bi prevladali te dva problema. Konvergencija puta nakon mrežnih promjena ovisi o tome kako se brzo informacije koje su dostavljene na čvorove, sudjeluju u istoj mreži. STP emitira informacije kako bi izgradio novu topologiju kada dođe do promjene mreže. Emitiranje traje određeno vrijeme koje je prihvatljivo za stvarno vremensku komponentu aplikacije. Dok STP koristi emitiranje, SPB koristi podatke baze podataka koja sadržava stanja linka. Čvorovi u mreži dobivaju informaciju stanja linka baze podataka odmah nakon promjene mreže čime SPB nudi prihvatljivo vrijeme konvergencije za stvarnu vremensku komponentu aplikacije. Suboptimalna veza iskorištenosti je još jedan problem za primjenu STP na oblak-podatkovnom centru. Za razliku od STP-a , SPB koristi linkove u višim slojevima podatkovnog centra. Prvo važna stvar, SPB ne zahtijeva odvajanja čvora jednog od drugog, kako bi se spriječilo stvaranje petlje. Drugo stvar, promet u SPB mreži uvijek uzima optimalan put u smislu veze troškova. Dok se korisničke mreže izoliraju od mreža pružatelja usluga, pružatelji moraju primijeniti različite usluge ili politike na korisnike prometa. Ova situacija se događa i u oblaku-podatkovnog centra također. IEEE 802.1aq enkapsulira korisnika prometa i dodjeljuje različite usluge identifikatore na kupca prometa. To daje mrežnim davateljima mogućnost da pruže različite razine korisničkih ugovora o uslugama za svakog korisnika. SPB usvaja sve značajke koje oblak-podatkovni centri mreže zahtijevaju. Buduća područja istraživanja usmjerena su kako održati svojstvo simetrične kongruencije između jednodredišnog i višeodredišnog emitiranja, te kako ostvariti najkraći put za prema zadanom odredištu (njegovom VID-u). Vidljive su dvije perjanice čemu bi trebali težiti : 1. Ukupno „tijelo“ Etherneta pod OAM protokolom 2. Poboljšanje Ethernetovog svojstva skaliranjaEthernet has evolved to support various network topologies while maintaining its backward compatibility and simplicity. Virtualization of the provider’s Ethernet network enables support for fine-grained services for different users. Spanning Tree Protocol (STP) meets these properties but, still could benefit from improvements on utilization and convergence time. Shortest Path Bridging (SPB, IEEE 802.1aq) has been developed to overcome these shortcomings of STP. In this thesis report I present the design of an network running RSTP and results of those simulations. Also I deducted some conclusions from SPB simulations where results prove that the communication maintains the crucial property of SPB; congruency between multicast and unicast, and symmetry between forward and backward paths. The traffic route selected among candidate paths with the same cost is in accordance with the SPB standard. SPB standard is not the only one in reconsideration so this thesis includes analysis between SPB competitors, TRILL and MLAG. Analysis are more oriented on differences between protocols because all of them have some advantages and disvantages, it is more focused on vendor who supports them

Projektiranje i karakterizacija višeprolaznih elektrooptičkih sklopova za širokopojasno mjerenje napona u elektromagnetski zagađenoj okolini

Broadband electro-optical differential probes for voltage measurements in an electromagnetically polluted environment are designed and characterized. The differential circuit topology is used because of its good immunity to noise. By separating the signal acquisition and signal processing part of the system, a fully isolated measurement system is implemented, where both the measured RF signal and the bias signal are transmitted using an optical connection. The probe circuit consists of the attenuator, the laser, and the bias circuit. Each part of the probe circuit is characterized by performing measurements, electromagnetic and circuit simulations, and circuit modelling. The simple and low cost measurement system is designed for characterization of electrostatic discharge waveforms. Scientific contribution of the doctoral thesis: 1. Methodology combining admittance parameters and mixed-mode scattering parameters for modelling electro-optical devices and for characterizing differential-mode and common-mode response. 2. Differential electro-optical equivalent circuit model of a vertical-cavity surface-emitting laser for common-mode rejection ratio estimation. 3. Design and characterization of multiport broadband electro-optical differential probes for voltage measurements in an electromagnetically polluted environment. 4. Comparative analysis of the floating-ground and connected-ground differential electro-optical voltage probes operating in GHz-range.U sklopu rada projektiraju se i karakteriziraju širokopojasne elektrooptičke diferencijske sonde za mjerenje napona u elektromagnetski zagađenoj okolini. Diferencijska topologija sklopa koristi se zbog dobre otpornosti na smetnje. Odvajanjem dijela sustava za mjerenje i obradu signala ostvaruje se potpuno izolirani mjerni sustav, gdje se i mjereni radiofrekvencijski signal i signal napajanja prenose optičkom vezom. Sklop sonde sastoji se od atenuatora, lasera i sklopa za napajanje. Svaki dio sklopa sonde karakterizira se provođenje mjerenja, elektromagnetskih i sklopovskih simulacija te modeliranjem. Ovaj jednostavan mjerni sustav niske cijene dizajniran je za karakterizaciju elektrostatskih izboja. Znanstveni doprinos doktorskog rada: 1. Metodologija za modeliranje elektrooptičkih sklopova i karakterizaciju odziva na diferencijske i zajedničke signale kombinacijom admitancijskih parametara i mješovitih raspršnih parametara. 2. Diferencijski elektrooptički nadomjesni model lasera s vertikalnom rezonantnom šupljinom za procjenu faktora potiskivanja zajedničkog signala. 3. Projektiranje i karakterizacija višeprolaznih širokopojasnih elektrooptičkih diferencijskih sondi za mjerenje napona u elektromagnetski zagađenoj okolini. 4. Usporedna analiza diferencijskih elektrooptičkih naponskih sondi s plivajućom masom i sa spojenom masom za rad u gigahercnom frekvencijskom području