PhD Candidate · ICMC-USP

Bruna Campos Guedes

I study when relational information between individuals can improve machine learning on small, heterogeneous healthcare datasets — and how to evaluate those models reliably.

São Carlos, Brazil Relational ML & Graph Neural Networks AI for Healthcare

About

Machine learning across biomedical engineering, neuroscience, and real-world systems.

I am a PhD candidate at the Institute of Mathematics and Computer Sciences, University of São Paulo (ICMC-USP). My current research focuses on relational machine learning and graph neural networks for heterogeneous Alzheimer-related data, with particular interest in population similarity graphs and inductive inference for unseen individuals.

My background combines Biomedical Engineering, computational neuroscience, and industry machine learning. I conducted fMRI research at the University of Bristol and later worked as a Junior Data Scientist at unico IDTech, where I developed and evaluated machine-learning systems under class imbalance, data scarcity, and production constraints.

Graph Neural Networks Relational Learning AI for Healthcare Reliable Small-Data ML

Current Research

Population similarity graphs for reliable learning from heterogeneous clinical data.

My doctoral work investigates whether relational inductive biases can improve cognitive-status modeling when datasets are small, heterogeneous, and moderately imbalanced. The central idea is to represent participants not only by their individual features, but also by their similarity relationships to other participants.

01

Heterogeneous data

Clinical and sociodemographic participant variables.

02

Representation

Participant-level latent representations from heterogeneous inputs.

03

Similarity graph

Participants connected according to learned or defined similarity.

04

Graph learning

Relational information propagated with graph neural networks.

05

Evaluation

Cognitive-status prediction under leakage-controlled validation.

Inductive inference: new participants are connected to the learned population structure and evaluated without rebuilding the full training pipeline.

Research Questions

01 · RELATIONAL SIGNAL

When does relational information help?

I compare graph-based learning with models that treat participants independently to determine when population structure provides a measurable advantage.

02 · GENERALIZATION

How should graph models handle new participants?

I investigate inductive inference protocols that connect unseen individuals to the learned population structure without rebuilding the full training system.

03 · RELIABILITY

How reliable are conclusions from small clinical datasets?

I use leakage-controlled nested validation, robustness analysis, class-specific evaluation, and ablation studies to separate promising patterns from unstable results.

Projects

Open and reproducible work spanning graph learning, neuroimaging, and interpretable machine learning.

Graph neural network message-passing diagram
Graph → message passing → prediction
Graph learning Public repository

GNN from Scratch

A from-scratch implementation of graph neural network foundations, including automatic differentiation, graph operations, GCN and GAT models, and reproducible experiments on Cora.

Graph Neural Networks GCN GAT NumPy
View repository
Functional-connectivity matrix and brain network diagram
Correlation matrix → functional network
Neuroimaging Reproducibility project

fMRI Connectivity Similarity

Reconstruction and modernization of earlier neuroimaging research on correlation methods and functional connectivity, with an emphasis on transparent, reproducible analysis.

fMRI Connectivity Neuroscience Reproducibility
View repository
Individual Conditional Expectation and Ceteris Paribus curve diagram
Individual curves + focal explanation
Explainability In development

Interpretable ML Methods

Reusable Python implementations of model-agnostic interpretability methods, including Ceteris Paribus and Individual Conditional Expectation analyses across multiple datasets.

Explainable AI Ceteris Paribus ICE Python
View repository

Education & Experience

A path from biomedical engineering to relational machine learning.

2024 – Present

PhD in Computer Science (Artificial Intelligence)

University of São Paulo · ICMC-USP

Advisor: Prof. André Carlos Ponce de Leon Ferreira de Carvalho

Research on relational integration of heterogeneous Alzheimer-related data using population similarity graphs, graph neural networks, rigorous evaluation, and inductive inference.

2021 – 2023

Junior Data Scientist

unico IDTech

Developed and evaluated machine-learning systems for large-scale identity verification, working with class imbalance, data scarcity, latency constraints, and GAN-based synthetic-data generation.

May – August 2019

Research Intern in Computational Neuroscience

University of Bristol · School of Engineering Mathematics and Technology

Supervisor: Prof. Naoki Masuda

Investigated correlation methods in fMRI data from individuals with autism spectrum disorder, focusing on functional relationships and brain-connectivity patterns.

2018 – 2019

Academic Exchange in Biomedical Engineering

Polytech Marseille · Aix-Marseille Université · France

International academic mobility during the Biomedical Engineering degree, supported by CAPES/BRAFITEC.

2015 – 2022

BSc in Biomedical Engineering

Federal University of Uberlândia · Biomedical Engineering

Undergraduate training in biomedical engineering, signal processing, and neuroimaging, including research on correlation methods applied to functional MRI.

Selected Publications

Early work across biomedical engineering, signal processing, and mathematical modeling.

2019Conference paper

Desenvolvimento de um sistema de controle para diluição automática de desinfetantes

XII Simpósio de Engenharia Biomédica / IX Simpósio de Instrumentação e Imagens Médicas.

DOI
2018Conference paper

Dispositivo para monitoramento de estresse através de biofeedback

XI Simpósio de Engenharia Biomédica.

DOI
2018Conference paper

Comparação eletromiográfica do músculo reto femoral entre indivíduos sedentários e não sedentários

XI Simpósio de Engenharia Biomédica.

DOI
2017Conference paper

Serious Game para Reabilitação Motora Utilizando Sinais Eletromiográficos

V Congresso Brasileiro de Eletromiografia e Cinesiologia / X Simpósio de Engenharia Biomédica.

DOI
2017Conference paper

O Problema de Geometria de Distâncias Moleculares Discretizável

XVII Semana da Matemática / VII Semana da Estatística, Federal University of Uberlândia.

Full research record

Additional conference work and abstracts are available through my research profiles.

ORCID  ·  Google Scholar  ·  Lattes

Methods & Tools

Machine Learning

PyTorch · PyTorch Geometric · scikit-learn · XGBoost

Scientific Computing

Python · MATLAB · C++ · NumPy · Pandas · NetworkX

Experimental Methods

Nested cross-validation · Robustness analysis · Ablations · Model explainability

Beyond Research

Community involvement, recognition, and languages that complement my academic profile.

Community

Volunteer Project Assistant at Data Girls (2023–2025), supporting outreach and mentorship initiatives for women in technology.

Recognition

Winner of the 2017 Innovations in Electromyography & Kinesiology competition; OBMEP bronze medalist (2010, 2015) with three honorable mentions.

Languages

Portuguese (Native) · English (B2) · French (B1)

Contact

Research collaborations and academic inquiries.

Location

São Carlos, Brazil

Research Profiles

ORCID  ·  Lattes  ·  Scholar