Banca de QUALIFICAÇÃO: VINICIUS DE PAULA SILVA

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : VINICIUS DE PAULA SILVA
Date: 06/10/2026
TIME: 09:00
LOCAL: Sala 107 Bloco Zeta Campus São Bernardo do Campo
TITLE:

An Open-Source Platform for Synchronized Multimodal Mapping and Analysis of Ex Vivo Hearts

PAGES: 100
BIG AREA: Engenharias
AREA: Engenharia Biomédica
SUBÁREA: Bioengenharia
SPECIALTY: Processamento de Sinais Biológicos
SUMMARY:

 

Introduction: Experimental cardiac electrophysiology increasingly relies on the integration of complementary mapping techniques to characterize electrical activity across different spatial scales. Optical mapping provides high-resolution visualization of electrophysiological activity, while electrical mapping provides direct extracellular recordings that are more closely related to clinical electrophysiology. Combining these modalities within the same preparation requires stable perfusion, precise synchronization, controlled stimulation, physiological monitoring, and coordinated data acquisition. Integrated experimental platforms capable of providing these functions are therefore important for reproducible investigation of cardiac propagation and arrhythmia mechanisms across different experimental models.

Aims: To develop and evaluate an integrated platform for synchronized optical and electrical mapping of ex vivo hearts, applicable across small- and large-heart preparations, and to establish the experimental and analytical framework required for subsequent investigation of local activation time (LAT) annotation and spatial interpolation methods.

Methods: The platform integrates controlled perfusion, electrical stimulation, physiological monitoring, synchronized multimodal acquisition, and software-based experimental control. The small-heart configuration, validated in Langendorff-perfused rabbit hearts, combines panoramic optical mapping, epicardial multi-electrode array recordings, and tank-based body surface potential mapping. Large-heart whole-organ and epi-endo configurations were implemented and validated for porcine and human ex vivo hearts, with adaptations in coronary perfusion, mechanical support, optical coverage, electrode geometry, and three-dimensional reconstruction. Electrical signals were acquired at 4 kHz and optical signals at 500 frames/s using a TTL signal as a synchronization method between modalities. Custom software was used to coordinate stimulation, acquisition, physiological monitoring, metadata recording, and experimental logging. An array of sensors, including pressure, flow rate and temperature was used during experiments to monitor the physiological characteristics of the perfusion solution.

Results: The developed platforms enabled synchronized acquisition of optical and electrical activity in rabbit, porcine, and human ex vivo hearts under organized and arrhythmic rhythms. In the small-heart configuration, simultaneous optical, epicardial, and tank recordings demonstrated temporal correspondence between modalities while preserving their expected differences in waveform morphology and spatial resolution. The large-heart platform enabled complementary whole-heart and dual-surface epi-endo optical and electrical mapping. The integrated control architecture also provided synchronized stimulation, continuous monitoring of perfusion variables, and structured documentation of experimental events. Together, these results demonstrate the feasibility and scalability of the proposed multimodal framework.

Next steps: The next stage of the project will use the synchronized optical and electrical datasets to investigate how different LAT annotation and spatial interpolation approaches influence electrically derived activation maps. Annotation methods based on electrogram slopes, deflections, peaks, electroanatomic mapping criteria, and more advanced spatiotemporal or signal-processing approaches will be compared. Spatial interpolation methods including nearest-neighbor, Delaunay-based linear, natural-neighbor, spline, Gaussian-process, and distance-constrained approaches will also be evaluated. High-resolution optical activation maps will be used as a reference to assess temporal accuracy, spatial agreement, preservation of activation patterns and gradients, and robustness to electrode density and signal characteristics.

Conclusions: The developed platform provides a scalable framework for synchronized optical and electrical investigation of cardiac electrophysiology in ex vivo preparations. Its integration of perfusion, stimulation, physiological monitoring, multimodal acquisition, and experimental control supports reproducible studies across different cardiac scales and provides the experimental basis for future methodological evaluation of cardiac activation mapping.

COMMITTEE MEMBERS:
Presidente - Interno ao Programa - 1188948 - JOAO LAMEU DA SILVA JUNIOR
Membro Titular - Examinador(a) Externo à Instituição - RÉMI DUBOIS
Membro Titular - Examinador(a) Externo à Instituição - JURANDIR NADAL - UFRJ
Membro Suplente - Examinador(a) Interno ao Programa - 2188954 - ERICK DARIO LEON BUENO DE CAMARGO
Membro Suplente - Examinador(a) Externo à Instituição - JEFFERSON LUIZ BRUM MARQUES - UFSC