Phone cam array - An open-source, modular photogrammetry system made of Android phones.

Area of Science:

• Medical Imaging
• Photogrammetry
• Forensic Medicine

Background:

• Photogrammetry enables 3D reconstruction from multiple photographs.
• Subject movement during image capture can compromise 3D model accuracy.
• Multi-camera systems offer a solution to mitigate motion artifacts.

Purpose of the Study:

• To develop a fast and precise tool for wound documentation in clinical forensic medicine.
• To create a low-cost, modular system using networked smartphones as cameras.
• To evaluate the effectiveness of a multi-smartphone photogrammetry system for 3D wound reconstruction.

Main Methods:

• A system utilizing multiple smartphones from different manufacturers as networked cameras was designed.
• A simple circuit synchronized simultaneous image capture across all devices.
• A proof-of-concept device with four smartphones mounted on a 3D-printed frame was constructed.

Main Results:

• The average image capture delay between the fastest and slowest phones was 636 ms.
• The multi-camera system did not reduce 3D model quality compared to single-camera methods.
• The phone camera array demonstrated reduced susceptibility to movement artifacts from breathing.
• Accurate wound assessment was achievable using the generated 3D models.

Conclusions:

• A low-cost, multi-smartphone photogrammetry system is effective for precise 3D wound documentation.
• This system offers a practical solution for clinical forensic medicine, overcoming limitations of single-camera approaches.
• The developed tool provides reliable 3D models for wound assessment, even with subject movement.