Research

Current research, plus two DOI-archived papers

The featured project is active right now — methodology and scope are locked in, results are not, and that's stated plainly below.

Current research
2026· NCAI, UET Lahore · Manuscript in preparation

Semi-Supervised Melanoma Nuclei Segmentation for Computer-Aided Diagnosis

Melanoma is diagnosed by pathologists manually examining histopathology slides — can a model learn to segment the relevant cell nuclei from only a handful of labeled examples?

Abstract

Expert-labeled medical images are expensive and scarce in practice, which makes fully supervised nuclei segmentation for melanoma histopathology hard to scale. This project tests whether semi-supervised learning can close that gap. Working with the PUMA histopathology dataset (205 annotated images), a U-Net segmentation baseline reached 0.91 Dice under full supervision — within 1.2 points of the 0.916 Dice reported by the benchmark study this work builds on (Akbarpour et al., J. Imaging 11(8):274, 2025). Four semi-supervised techniques — Mean Teacher consistency regularization, a semi-supervised GAN, autoencoder pretraining, and confidence-based pseudo-labeling — were then rigorously compared against a matched supervised baseline under simulated label scarcity (15 and 40 labeled images). The manuscript is currently being written.

Contributions

  • A U-Net supervised baseline on the PUMA dataset reaching 0.91 Dice, closely matching the benchmark study it's compared against
  • A controlled comparison of four distinct semi-supervised techniques — Mean Teacher, semi-supervised GAN, autoencoder pretraining, and pseudo-labeling — against the same supervised baseline under simulated label scarcity
  • A demonstration that GAN-based semi-supervision reaches near-parity with full supervision using only 15 labeled images
  • A follow-up domain-diversity experiment using real out-of-domain histopathology data sourced from the public TCGA-SKCM archive via the NIH GDC API

Methodology

01

U-Net segmentation baseline trained under full supervision on the PUMA dataset, benchmarked directly against Akbarpour et al.'s published Dice score

02

Four semi-supervised methods implemented and compared under matched conditions: Mean Teacher consistency regularization, a semi-supervised GAN, autoencoder pretraining, and confidence-based pseudo-labeling

03

Simulated label scarcity at 15 and 40 labeled images, with every method evaluated against the same supervised baseline at the same label counts

04

A domain-diversity ablation sourcing real out-of-domain histopathology data from TCGA-SKCM via the NIH GDC API, to test whether unlabeled-data diversity — not just quantity — affects semi-supervised performance

H&E histopathology corpusexpert-labeled + unlabeled slidesLabeled subsetexpert-annotated, smallSupervised signalmelanoma / benignUnlabeled subsetfar larger, no annotationRepresentation learningautoencoder / self-supervisedConsistency / pseudo-labelconfidence-gatedSemi-supervised trainingCNN / ViT backbone · joint objectiveMelanoma prediction · Sensitivity · Specificity · ROC-AUC

Status

Supervised baseline (U-Net, full supervision)

0.91 Dice

Benchmark comparison

within 1.2 pts of Akbarpour et al.'s 0.916 Dice

Best SSL method at 15 labeled images

GAN-based SSL — 0.869 Dice vs. 0.870 supervised

Out-of-domain diversity ablation (TCGA-SKCM)

partially closed the gap, did not surpass supervised training

Datasets

  • PUMA histopathology dataset — 205 expert-annotated melanoma images (labeled component)
  • TCGA-SKCM (The Cancer Genome Atlas, skin cutaneous melanoma), sourced via the NIH GDC API — out-of-domain unlabeled data for the follow-up diversity experiment

Stack

Python
PyTorch
U-Net
OpenCV
NumPy
Pandas

Current focus

  • GAN-based semi-supervision reached near-parity with full supervision using only 15 labeled images (0.869 vs. 0.870 Dice) — the strongest of the four methods tested at that label count
  • A stalled result in one setting was traced to insufficient domain diversity in the unlabeled pool, not a weakness in the method itself
  • Sourcing real out-of-domain histopathology data from TCGA-SKCM to directly test that diagnosis: added diversity partially closed the gap under controlled ablation, but did not surpass supervised training
  • The four SSL techniques were evaluated under genuinely matched conditions — same baseline, same label counts, same evaluation protocol — rather than each being reported against its own best-case setup

Stated plainly

  • Results are from the PUMA dataset and a TCGA-SKCM out-of-domain ablation — not yet validated on a held-out clinical cohort
  • The manuscript describing this work is still being written; a preprint or venue hasn't been finalized yet
  • Computer-aided diagnosis here is intended as pathologist decision support, not a validated standalone clinical tool

Earlier work

Other published research

2026
Independent research · DOI-archived on Zenodo

MedInsight: Evaluating Retrieval-Augmented Vision-Language Models for Evidence-Grounded Medical Image Understanding

MedInsight tests whether retrieval-augmented prompting improves a vision-language model's accuracy on medical visual question answering, using only openly licensed, non-credentialed data. A CLIP-embedded FAISS index over ~90,000 ROCOv2 radiology image-caption pairs supplies retrieved evidence captions to a pretrained BLIP-2 model, and that retrieval-augmented condition is compared against the same model answering with no retrieved evidence at all — same checkpoint, same decoding settings, same scoring code, on the official VQA-RAD test split (451 clinician-authored questions), with paired bootstrap significance testing rather than a single reported delta.

Python
PyTorch
BLIP-2
CLIP
FAISS
Retrieval-Augmented Generation
Vision-Language Models
Hugging Face Transformers
2024 – 2025
Independent research · DOI-archived on Zenodo

AI-Based Depression Detection from Social Media Using LSTM Networks

This research investigates whether Long Short-Term Memory (LSTM) networks can pick up linguistic and behavioral indicators of depression in social media text more reliably than simple bag-of-words baselines. NLP preprocessing (tokenization, cleaning, stopword removal, embedding generation) feeds a sequence model trained to classify posts as depression-indicative or not, with class-imbalance handling and standard classification metrics.

Python
TensorFlow/PyTorch
LSTM
NLP
Pandas
NumPy