# Posture-Transformed Monkey Phantoms Developed from a Visible Monkey
###### Abstract  
A monkey phantom is of significant value for electromagnetic radiation (EMR) dosimetry simulations. Furthermore, phantoms in various postures are needed because living beings are exposed to EMR in various postures during their daily routine. In this study, we attempted to produce monkey phantoms based on three daily postures of a rhesus monkey. From our Visible Monkey project, we selected surface models with 177 monkey structures. In the surface models, 52 virtual joints were created to allow for changes from the anatomical position to quadrupedal and sitting positions using commercial software. The surface models of the three positions were converted into monkey voxel phantoms. These phantoms were arranged in three positions, and the number of voxels and mass of each structure were analyzed. The phantoms in anatomical, quadrupedal, and sitting positions have a total of 5,054,022, 5,174,453, and 4,803,886 voxels, respectively. The mass of 177 structures in three positions were also calculated based on the number of voxels. By comparing the monkey phantom with the phantom of a female human, we confirmed thicker skin, less fat, heavier muscle, and a lighter skeleton in monkeys than those in humans. Through postures-transformed monkey phantoms, more precise EMR simulations could be possible. The ultimate purpose of this study is to determine the effects of EMR on humans. For this purpose, we will create posture-transformed human phantoms in a following study using the techniques employed herein and the human phantoms from our previous study.  
electromagnetic radiation; phantom; haplorhini; visible human project; three-dimensional imaging +
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The second hindrance is the availability of only one posture in existing phantoms. Most phantoms are produced in a supine position from CT or MRI data [1; 2; 3; 4; 5; 6; 7; 8]. To accurately simulate the EMR effects on a phantom, the phantoms must be exposed to electromagnetic waves during specific postures because the tissues and organs of living creatures may be influenced differently depending on posture [9; 19; 20]. In a recent study, a posture-transformed human phantom was produced for EMR simulation. However, the techniques required to create the phantom were so professional that researchers unfamiliar with mathematical algorithms cannot easily repeat the technique [9].  
For verifying MRI stability, EMR simulations based on a monkey phantom of only one anatomical position has been recently produced [21]. The monkey phantom was made from data of our Visible Monkey project [22]. However, if an EMR simulation is conducted not only for medical devices but also for electronic devices on a monkey phantom, then the original posture of the phantom will be unsuitable because living monkeys are exposed to electromagnetic radiation in different postures during their daily routines. To address this limitation, a phantom was needed that can assume common postures in the everyday life of a monkey [23; 24; 25; 26].  
The primary aim of this study was to present posture-transformed monkey phantoms that are able to assume anatomical, quadrupedal, and sitting positions among the most common everyday postures used for EMR simulations. The secondary aim was to present easy methods for making posture-transformed phantoms using commercial software. To achieve these aims, in this study, surface models of Visible Monkeys in anatomical positions [27] were transformed into models in quadrupedal and sitting positions and then converted into voxel phantoms.