---
license: mit
tags:
  - medical-imaging
  - ophthalmology
  - image-classification
  - explainable-ai
  - grad-cam
  - core-ml
  - resnet
  - pytorch
language:
  - zh
  - en
metrics:
  - roc_auc
  - f1
pipeline_tag: image-classification
---

# ELIAS — Eyelid Lesion Intelligent Analysis System

**眼瞼疾病智慧分析系統**

> 🏆 2026 年經濟部智慧創新大賞（學生組）參賽作品

---

## Model Description

ELIAS is a **clinician-guided deep learning classifier** for automated detection of **epiblepharon** (睫毛倒插) from external eye photographs.

The model uses a **frozen ImageNet-pretrained ResNet-18 backbone** with a task-specific classification head. The key innovation is the explicit integration of clinician-defined anatomical **Regions of Interest (ROI)** — specifically the lower eyelid margin and eyelash–cornea interface — as a prior constraint, enabling robust classification in a **small-data regime (~80–150 cases per class)**.

### Architecture

```
Input (224×224 RGB)
    │
    ▼
ResNet-18 backbone (frozen, ImageNet pretrained)
    │  layer1 → layer2 → layer3 → layer4
    │  Global Average Pooling → (512,)
    ▼
Dropout(0.3) → Linear(512 → 2)
    │
    ▼
Softmax → [P(control), P(epiblepharon)]
```

| Component | Detail |
|---|---|
| Backbone | ResNet-18 (ImageNet pretrained, **fully frozen**) |
| Classification head | `Dropout(0.3)` + `Linear(512 → 2)` |
| Loss function | `CrossEntropyLoss` |
| Optimizer | `Adam(lr=1e-3)`, head parameters only |
| Input size | 224 × 224 px, RGB (Grayscale → 3ch conversion applied) |
| Normalization | ImageNet mean/std `[0.485, 0.456, 0.406]` / `[0.229, 0.224, 0.225]` |

---

## Performance

Evaluated by **stratified 5-fold cross-validation** (`random_state=42`, 20 epochs/fold).

| Metric | Mean (5-fold) |
|---|---|
| **AUC** | **0.93** |
| Accuracy | High |
| Sensitivity | High |
| Specificity | Moderate |
| F1 Score | High |

- ✅ No fold collapse observed across all 5 folds
- ✅ Label-shuffling negative control confirmed genuine feature learning
- ✅ ROI ablation experiments validated lower eyelid margin as primary diagnostic signal

### ROI Ablation Summary

| Condition | Performance vs Baseline |
|---|---|
| Full image (baseline) | ✅ Optimal |
| ROI ablated (lower eyelid blurred) | ❌ Significant drop |
| Non-ROI ablated (ROI preserved) | ✅ Near-baseline |

> Diagnostic features are **spatially localized** to the clinically defined lower eyelid margin — consistent with clinical examination principles for epiblepharon.

---

## Grad-CAM Explainability

Grad-CAM heatmaps were generated using native PyTorch hooks on `layer4` (no Captum dependency):

- **Epiblepharon cases**: Activation consistently focused on **lower eyelid margin and eyelash–cornea interface**
- **Control cases**: Diffuse, anatomically unfocused activation patterns

Heatmap overlay: α = 0.45, JET colormap, bilinear upsampling to 224×224.

---

## iOS On-Device Inference

The trained model has been converted to **Apple Core ML** format (`.mlpackage`):

| Metric | Value |
|---|---|
| Model size | < 50 MB |
| Inference latency | **< 1 second / image** |
| Device | iPhone 12+ (A14+ Neural Engine) |
| Network required | ❌ None — fully on-device |

Privacy: facial images never leave the device, consistent with PDPA / HIPAA principles.

---

## Training Data

- **Task**: Binary classification — epiblepharon vs. control
- **Image type**: External eye photographs
- **Dataset size**: ~80–150 cases per class (single-center, retrospective)
- **Preprocessing**: Resize 224×224, Grayscale→3ch, ColorJitter, RandomHorizontalFlip, ImageNet normalization

> ⚠️ Clinical images are **not distributed** in this repository due to patient privacy regulations (Personal Data Protection Act, IRB). For academic collaboration, please contact the corresponding author.

---

## Usage

```python
import torch
from torchvision import models, transforms
from PIL import Image

# Load model
model = models.resnet18(weights=None)
for param in model.parameters():
    param.requires_grad = False
model.fc = torch.nn.Linear(model.fc.in_features, 2)
model.load_state_dict(torch.load("pytorch_model.pt", map_location="cpu"))
model.eval()

# Preprocess
transform = transforms.Compose([
    transforms.Resize((224, 224)),
    transforms.Grayscale(num_output_channels=3),
    transforms.ToTensor(),
    transforms.Normalize([0.485, 0.456, 0.406], [0.229, 0.224, 0.225]),
])

img = Image.open("eye_photo.jpg").convert("RGB")
x = transform(img).unsqueeze(0)  # (1, 3, 224, 224)

with torch.no_grad():
    logits = model(x)
    prob = torch.softmax(logits, dim=1)[0, 1].item()
    print(f"Epiblepharon probability: {prob:.3f}")
```

---

## Files in This Repository

| File | Description |
|---|---|
| `README.md` | This model card |
| `model.py` | Model architecture definition |
| `train.py` | 5-fold cross-validation training script |
| `config.json` | Model configuration |
| `requirements.txt` | Python dependencies |
| `pytorch_model.pt` | *(Checkpoint — upload separately after training)* |

---

## Intended Use & Limitations

- **Intended use**: Research prototype for clinical decision support in epiblepharon screening
- **NOT** a validated medical device — prospective evaluation and regulatory assessment required before clinical deployment
- Single-center retrospective data — generalizability across imaging conditions and demographics requires multi-center validation

---

## Citation

```bibtex
@misc{elias2026,
  title     = {ELIAS: Eyelid Lesion Intelligent Analysis System},
  year      = {2026},
  note      = {2026 MOEA Smart Innovation Award submission},
  url       = {https://huggingface.co/YOUR_HF_USERNAME/ELIAS-epiblepharon}
}
```

---

## License

[MIT License](LICENSE) — Source code only. Clinical data excluded.