# Mechanically Powered Motion Imaging Phantoms: Proof of Concept

## TL;DR

This paper presents a cost-effective, portable, mechanically powered motion imaging phantom using springs and elastic bands, capable of producing reproducible motion for MRI and ultrasound imaging validation.

## Contribution

It introduces a novel mechanically powered phantom design that is simple, affordable, and suitable for multi-modality motion imaging validation.

## Key findings

- Reproducible angular velocity measurements from imaging sequences.
- Successful use of Laplacian Eigenmap for motion analysis.
- Potential for easy construction of motion phantoms.

## Abstract

Motion imaging phantoms are expensive, bulky and difficult to transport and set-up. The purpose of this paper is to demonstrate a simple approach to the design of multi-modality motion imaging phantoms that use mechanically stored energy to produce motion. We propose two phantom designs that use mainsprings and elastic bands to store energy. A rectangular piece was attached to an axle at the end of the transmission chain of each phantom, and underwent a rotary motion upon release of the mechanical motor. The phantoms were imaged with MRI and US, and the image sequences were embedded in a 1D non linear manifold (Laplacian Eigenmap) and the spectrogram of the embedding was used to derive the angular velocity over time. The derived velocities were consistent and reproducible within a small error. The proposed motion phantom concept showed great potential for the construction of simple and affordable motion phantoms