Coherent fluctuating nephelometry application in laboratory practice
Kuupäev
2018-07-02
Autorid
Ajakirja pealkiri
Ajakirja ISSN
Köite pealkiri
Kirjastaja
Abstrakt
Käesolev doktoritöö on pühendatud uue optilise meetodi – koherentse fluktuatsiooni nefelomeetria (i.k. coherent fluctuation nephelometry, CFN) – uurimisele ja praktilisele rakendamisele. See on uus lähenemine lahuste hägususe mõõtmiseks, kasutades selleks hajunud valguse mõõtmist. Sel lähenemisel on mitmeid eeliseid võrreldes tavapärase nefelomeetrilise meetodiga, mille tundlikkust piirab hajunud valguse foon, mis pärineb eelkõige küvetilt, aga ka kõikidelt süsteemi teistelt optilistelt osadelt. CFN põhineb hajunud valguse ajalise fluktuatsiooni mõõtmisel, nii et kasulik signaal pärineb ainult liikuvatelt osakestelt küveti vedelikus ning süsteemi mitteliikuvad osad ei mõjuta peaaegu üldse signaali. See võimaldab saavutada paremat tundlikkust, lihtsustada seadme konstruktsiooni ning kasutada ühekordseid madala optilise kvaliteediga küvette.
Nefelomeetria on laialdaselt kasutusel teaduslikes ning laboratoorsetes rakendustes (nt meditsiinilaborites) hindamaks proovide hägusust ning monitoorimaks protsesse, mille käigus hägusus muutub. Suure tundlikkuse saavutamine nõuab seadme keerulisemaks muutmist ning kõrge optilise kvaliteediga küvettide kasutamist, mis peaksid olema kliinilistes laborites ühekordseks kasutamiseks mõeldud. CFN meetodi eelised võimaldavad konstrueerida efektiivsemaid seadmeid, millega olulisi probleeme meditsiinilabori praktikas lahendada.
Doktoritöö peamine ülesanne oli uurida CFN meetodit, et teha kindlaks optilise tee optimaalsed parameetrid ning arendada välja CFN-analüsaatorite prototüübid. Teine oluline ülesanne oli rakendada CFN meetodit, et lahendada olulisi probleeme kliiniliste laborite praktikas ning valida välja meetodi põhiline rahendusala.
CFN meetodit rakendati, et analüüsida erinevaid bioloogilisi proove ning osakeste suspensioone väikese ning suure hägususega. Põhitulemused saavutati immunoglutinatsiooni reaktsioonide ning mikroorganismide kasvukõverate salvestamise korral. CFN meetodi toimimise modelleerimine ning teoreetiline analüüs koos eksperimentaaltöö tulemustega võimaldasid arendada mitmekanalilise mikrobioloogilise analüsaatori eesmärgiga seda rakendada kliinilises mikrobioloogia laboris. Need seadmed hõlmavad endas nii CFN kui turbidimeetria meetodeid, et suurendada seadmete dünaamilist mõõteulatust. Analüsaatorites pole mitte mingeid mehaanilisi süsteeme küvettide positsioneerimiseks; CFN meetodi lihtsus võimaldab iga küveti jaoks kasutada eraldi valgusallikat ning fotodetektoreid, vähendades nii seadme keerulisust ning suurendades töökindlust.
CFN prototüüpe kasutati edukalt kliinilistes laborites, et lahendada kaht olulist probleemi: uriiniproovide kiir-skriining (sõelumine) ning antibiootikumide mikroobtundlikkuse kiir-testimine. Kokku tehti rohkem kui 900 mõõtmist, mille võrdluskatsed teiste mikrobioloogiliste meetoditega näitasid head kokkulangevust. Arendatud CFN analüsaatorid näidati olevat efektiivsed kliinilises mikrobioloogia laboris.
The thesis is devoted to investigation and application of the new optical method called coherent fluctuating nephelometry (CFN). It is the new approach to turbidity measurement by means of scattered light detection. It has several advantages in comparison with conventional nephelometry method, which has limited sensitivity due to parasitic stray light, scattered by all optical parts of the device, first of all by the optical cuvette. CFN is based on detecting of fluctuations of scattered light, so the signal is formed only by particles moving in the liquid in the cuvette, and light scattered by nonmoving parts of the device almost does not influence the signal. That allows to achieve higher sensitivity, to make the device simpler and to use disposable cuvettes of low optical quality. Nephelometry is widely used in scientific and laboratory applications (e.g. medical laboratory practice) for turbidity estimation and recording the processes causing turbidity changes. High sensitivity achievement requires complicating of the device and using cuvettes of high optical quality, which must be disposable in clinical laboratory practice. The advantages of CFN method allows to construct more efficient devices to solve important problems in medical laboratory practice. The main task was to investigate CFN method to determine optimal parameters of optical path to develop prototypes of CFN-analyzers. The other task was to apply CFN method for solving important problems in clinical laboratory practice and to choose main field of applicability. CFN was applied to analyze different biological samples and particles suspensions of low and high turbidity. The main results were achieved for immunoagglutination reactions and for recording of microorganisms growth curves. The result of modeling and theoretical analysis of CFN operation together with the results of experimental work allowed to develop multichannel microbiological analyzers for application in clinical microbiology laboratory. These devices combine CFN and turbidimetry methods to broad the dynamics range. Analyzers do not use any mechanical system of cuvettes positioning; the simplicity of CFN allows to use own light source and photodetectors for each cuvette, decreasing device complexity and increasing its reliability. CFN prototypes were successfully used in clinical microbiology laboratories to solve two important problems: fast urine screening and rapid antibiotic susceptibility testing. Altogether more than 900 test were done, the comparison with other microbiological methods showed good agreement. The developed CFN-analyzers were shown to be effective in clinical laboratory microbiology.
The thesis is devoted to investigation and application of the new optical method called coherent fluctuating nephelometry (CFN). It is the new approach to turbidity measurement by means of scattered light detection. It has several advantages in comparison with conventional nephelometry method, which has limited sensitivity due to parasitic stray light, scattered by all optical parts of the device, first of all by the optical cuvette. CFN is based on detecting of fluctuations of scattered light, so the signal is formed only by particles moving in the liquid in the cuvette, and light scattered by nonmoving parts of the device almost does not influence the signal. That allows to achieve higher sensitivity, to make the device simpler and to use disposable cuvettes of low optical quality. Nephelometry is widely used in scientific and laboratory applications (e.g. medical laboratory practice) for turbidity estimation and recording the processes causing turbidity changes. High sensitivity achievement requires complicating of the device and using cuvettes of high optical quality, which must be disposable in clinical laboratory practice. The advantages of CFN method allows to construct more efficient devices to solve important problems in medical laboratory practice. The main task was to investigate CFN method to determine optimal parameters of optical path to develop prototypes of CFN-analyzers. The other task was to apply CFN method for solving important problems in clinical laboratory practice and to choose main field of applicability. CFN was applied to analyze different biological samples and particles suspensions of low and high turbidity. The main results were achieved for immunoagglutination reactions and for recording of microorganisms growth curves. The result of modeling and theoretical analysis of CFN operation together with the results of experimental work allowed to develop multichannel microbiological analyzers for application in clinical microbiology laboratory. These devices combine CFN and turbidimetry methods to broad the dynamics range. Analyzers do not use any mechanical system of cuvettes positioning; the simplicity of CFN allows to use own light source and photodetectors for each cuvette, decreasing device complexity and increasing its reliability. CFN prototypes were successfully used in clinical microbiology laboratories to solve two important problems: fast urine screening and rapid antibiotic susceptibility testing. Altogether more than 900 test were done, the comparison with other microbiological methods showed good agreement. The developed CFN-analyzers were shown to be effective in clinical laboratory microbiology.
Kirjeldus
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Märksõnad
fluctuation phenomena, coherence, laboratory diagnosis, medical microbiology