Banca de QUALIFICAÇÃO: GIOVANNI LAZZARIN WEBER

Uma banca de QUALIFICAÇÃO de MESTRADO foi cadastrada pelo programa.
STUDENT : GIOVANNI LAZZARIN WEBER
DATE: 20/02/2024
TIME: 08:00
LOCAL: Sala 107 Bloco Zeta Campus São Bernardo do Campo
TITLE:

Development of a microelectrode array for epicardial mapping of isolated rabbit heart in an experimental setup

PAGES: 90
BIG AREA: Engenharias
AREA: Engenharia Biomédica
SUBÁREA: Bioengenharia
SPECIALTY: Processamento de Sinais Biológicos
SUMMARY:

Introduction: High-density recordings of the cardiac electrical activation sequence are valuable in research as they provide spatiotemporal and electrophysiological characterization of the biological tissues studied. Commercially available microelectrode arrays (MEAs) have been widely used to acquire this high-density electrophysiological information, but cannot be easily used on a rabbit heart, due to its small mapping area and geometry not consistent with the curvature of the epicardium.

 Objectives: The objective of this project is to develop a microelectrode array capable of mapping different areas of the epicardium, especially the left atrium of an isolated rabbit heart in Langendorff perfusion, acting together with optical mapping of electrical activity.

 Methods: Several versions of MEAs were created iteratively, validating their mechanical stability in contact with the epicardium of the mapped heart, quality of the electrical signal and interference with the optical mapping system. The MEAs were connected to a 64-channel headstage (Intan, USA), then connected to a 256-channel acquisition board (Open Ephys, USA) at a sampling rate of 2kHz per channel. After the heart was isolated, reperfused and inserted into a mapping tank, the MEAs were positioned in the left atrium and evaluated for the quality of the electrical signal acquired and stability of the electrical signals from the electrodes throughout the experiment. To evaluate the interference with the optical mapping system, the MEAs were characterized with a fiber optic spectrometer (Ocean Optics, USA) focusing on the fluorescence emission frequency range of the compound used for optical mapping, 730 nm.

 Results: The MEAs created were progressively modified, first by changing the base material from silicone to PET, significantly improving the transmittance at 730 nm and later by changing the material and increasing the electrode area in order to improve the quality of the acquired electrical signals, being the latest version composed of 0.40 mm thick PET sheet, 1 mm² platinum-iridium polished electrodes in a 4x4 matrix, connected through enameled cables to the acquisition system.

 Conclusions: The customized MEAs fulfilled their function, allowing the reliable and quality acquisition of epicardial electrical signals with minimal interference in the optical mapping system, only due to the electrodes themselves that prevent the transmission of the optical signal through the MEAs.

COMMITTEE MEMBERS:
Presidente - Interno ao Programa - 1610505 - DANIEL PAPOTI
Membro Titular - Examinador(a) Externo ao Programa - 1188948 - JOAO LAMEU DA SILVA JUNIOR
Membro Titular - Examinador(a) Externo ao Programa - 1718113 - ANA PAULA ROMANI
Membro Suplente - Examinador(a) Interno ao Programa - 2188954 - ERICK DARIO LEON BUENO DE CAMARGO
Membro Suplente - Examinador(a) Externo à Instituição - MATHEUS CARDOSO MORAES - UNIFESP
Membro Suplente - Examinador(a) Externo à Instituição - ALESSANDRO PEREIRA DA SILVA - UMC