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Medical AI Research

MedGraph

RAG

A Knowledge-Graph Grounded
Medical RAG System

From unstructured text to clinically meaningful, graph-grounded answers. Building interpretable, auditable medical QA.

Presented By

Ashwin • Aviral • Dally

Institution

Newton School of Technology

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Unstructured Data Challenges

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Medical literature and clinical records contain vast amounts of valuable information, but relying on traditional LLMs and unstructured retrieval creates critical safety and accuracy gaps.

Limited Multi-hop Reasoning

Simple vector retrieval fails to connect disparate facts scattered across different documents.

Entity Aliasing & Ambiguity

Inconsistent terminology breaks retrieval consistency without a unified knowledge schema.

"Black Box" Hallucinations

Standard LLMs generate plausible but unverified answers. Medical decisions require traceable evidence.

Problem Visualization
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Hybrid KG + RAG Pipeline

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Our solution integrates Named Entity Recognition (NER) with Knowledge Graphs to structure medical facts before retrieval, enabling precise, auditable answers grounded in explicit relationships.

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Input Text

Unstructured clinical notes

2

NER Extraction

spaCy + BERT + Gemini

3

Knowledge Graph

Structured Triplets

4

KG Retrieval

Traverse graph relations

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Grounded Answer

LLM generates response

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Extracting Medical Entities

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Entity Types

MEDICINE

Pharmaceutical names

Examples: Remdesivir, Ibuprofen, Aspirin

PATHOGEN

Bacteria, viruses

Examples: SARS-CoV-2, E. coli, Streptococcus

MEDICAL_CONDITION

Diseases, disorders

Examples: COVID-19, Pneumonia, Diabetes

Model Performance

75.5%
F1 Score
83.3%
Precision
69.0%
Recall

Model Architecture

• Token-to-Vector: MultiHashEmbed
• Transition-Based Parser (Hidden: 64)
• Training: 50 epochs, batch size 100

Annotation Strategy

Hybrid approach: automated NER combined with Gemini API for high-quality relationship extraction.

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From Entities to Structured Knowledge

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Pipeline Overview

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Entity Extraction
Use spaCy NER or Gemini API
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Relationship Extraction
Identify TREATS and CAUSES
3
Triplet Formation
Create (Subject) --[Relationship]--> (Object)
4
Graph Building
Construct graph using NetworkX
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Visualization
Visualize with Matplotlib

Example Triplets

(Remdesivir) --TREATS--> (COVID-19)
(SARS-CoV-2) --CAUSES--> (COVID-19)
Medical Knowledge Graph
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Chain of Exploration (CoE) Framework

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Chain of Exploration Architecture

Process Flow

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Exploration Plan
Break queries into sequential steps
2
LLM Evaluation
Refine approach for each step
3
KG Lookup
Cypher queries and vector search
4
RAG Answer
Generate accurate answers

Key Advantages

• Structured reasoning through knowledge graphs
• Multi-hop query support
• Transparent, traceable reasoning paths
• Superior accuracy on complex queries
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Achievements and Next Steps

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Key Achievements

NER Model

75.5% F1 score for medical entity extraction with 83.3% precision, successfully identifying MEDICINE, MEDICAL_CONDITION, and PATHOGEN entities.

Knowledge Graph

Comprehensive medical KG with TREATS and CAUSES relationships, enabling structured querying and multi-hop reasoning.

KG-RAG System

Chain of Exploration framework for complex multi-hop reasoning, outperforming vanilla LLMs and standard RAG systems.

Future Work

• Expand entity types and relationships
• Improve NER precision and recall
• Scale to larger medical corpora
• Integrate temporal and spatial data

Performance Comparison

Approach Complex Multi-hop Accurate
LLM Only
LLM + RAG
LLM + KG-RAG

Thank You!

MedGraph RAG

Team Members

Ashwin Sathyamoorthy Aviral Singh Dally R
View on GitHub