Biomechanical and optical characterization of epidermal tissue

[ A. Dragičević]

97 str.

Mašinstvo - Biomedicinsko inženjerstvo / Mechanical Engineering - Biomedical Engineering

Kolorektalni karcinom je jedan od glavnih zdravstvenih problema u razvijenim zemljama. Opto-magnetna imidzing spektroskopija (OMIS) kao nova metoda za karakterizaciju različitih vrsta materijala, uključujući i ljudska tkiva, se u ovoj Disertaciji po prvi put koristi za rano otkrivanje raka debelog creva. OMIS metoda zasniva se na interakciji svetlosti i materije i daje biofizičke parametre za karakterizaciju tkiva zdravo/bolesno. Da bi se izmerila razlika zaostalog magnetizma između zdravog tkiva i tkiva karcinoma debelog creva, primenjen je dvobrzinski spinner magnetometar JR-6A, sa tačnošću 2,4 A/m (3pT). Kako su ove dve metode komplementarne, JR-6A je korišćen da karakteriše ukupnu zapreminu tkiva i potvrdi da optomagnetna imidžing spektroskopija koja meri paramagnetna/dijamagnetna svojstva tkiva u tankim površinskim slojevima daje relevantne podatke za klasifikaciju zdravo/bolesno. OMIS spektri daju tačnost do 92.5% korišćenjem višeslojne neuronske mreže kao klasifikatora, dok podaci magnetometra na bazi parametarskog frakcionog računa daju tačnost 86.1%. Ovim je pokazano da obe metode jasno razlikuju zdravo tkivo od kancerogenog. Dobijeni rezultati pokazuju da bi se ova nova neinvazivna metoda mogla koristiti za karakterizaciju tkiva ex vivo. Međutim, kao takva OMIS metoda otvara mogućnost korišćenja u in vivo uslovima u kombinaciji sa modifikovanom kolonopskopijom što bi lekarima pomoglo u ranijem otkrivanju kancera debelog creva.

Colorectal carcinoma is one of the major health problems in industrialized countries. Opto-magnetic imaging spectroscopy (OMIS) as a new imaging method for the characterization of various materials, including human tissues, is used in this Dissertation for the first time for early detection of colon cancer. The OMIS method is based on light-matter interaction and allows biophysical criteria in tissue characterization, healthy/cancer. To measure the difference of the remanent magnetism between healthy and colon cancer tissue, a dual-speed spinner magnetometer JR-6A, with accuracy 2.4 A/m (3pT) was applied. As both of these methods are complementary to each other, JR-6A was used to characterize the total tissue volume and to confirm that opto-magnetic imaging spectroscopy measuring the paramagnetic/diamagnetic properties of tissue in thin surface layers providing relevant data for the healthy/cancer classification. OMIS spectra give an accuracy of up to 92.5% using the Perceptron multilayer neural network as a classifier, while magnetometer data give an accuracy of 86.1%. This shows that both methods clearly distinguish healthy tissue from cancer tissue. The obtained results indicate that this new non-invasive method could be used for ex vivo characterization. However, the OMIS method opens up the possibility of using the same method in in vivo studies in combination with modified colonoscopy to assist physicians in targeting biopsies of colorectal tissue.

Optomagnetna imidžing spektroskopija, kolorektalni karcinom, neuronske mreže, skrining, klasifikacija, diferencijacija tkiva

opto-magnetic imaging spectroscopy, colorectal cancer, neural networks, screening, classification, tissue differentiation

004.421:621.039.333:616.345-006.6((043.3)

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