Development of a quantitatively controlled expirated bloodstain generation system using an anatomically-informed oral...

Area of Science:

• Forensic Science
• Biomechanical Engineering
• Fluid Dynamics

Background:

• Expirated bloodstains, crucial in forensic investigations, are challenging to reproduce due to limitations in current methods.
• Misinterpretation of expirated stains as impact or cast-off patterns is a significant forensic concern.
• Existing reproduction techniques lack reproducibility, biosafety, and quantitative control.

Purpose of the Study:

• To develop and validate a novel system for generating expirated bloodstains under controlled airflow conditions.
• To address the limitations of conventional methods in expirated bloodstain reproduction.
• To create a tool for enhanced forensic training and automated bloodstain classification.

Main Methods:

• Integration of anatomically informed 3D-printed oral models simulating blowing and coughing.
• Utilization of a calibrated airflow control unit for precise modulation of air velocity and oral opening.
• Formulation of artificial blood with rheological properties matching human blood for consistent stain generation.

Main Results:

• The developed system successfully generated distinct expirated bloodstain patterns under controlled conditions.
• Morphological analysis quantified stain area, impact angle, and orientation, confirming pattern differentiation.
• The system demonstrated high reproducibility and quantitative control over stain generation.

Conclusions:

• The novel system provides a safe, reproducible, and quantifiable method for generating expirated bloodstains.
• This technology offers significant utility for forensic training and educational purposes.
• The generated datasets are valuable for developing machine learning and deep learning models for automated bloodstain classification.