Efficient Model Posing and Morphing Software

ABSTRACT: Studying the effects of electromagnetic energies on human anatomy requires the consideration how the effects change for different anatomical poses and body types, e.g., for different body-mass indexes. Acquiring such a wide range of data, however, can be problematic given medical scanner costs and acquisition requirements, e.g., the subject must be lying down for CT and MRI acquisitions. We propose to deliver software, documentation, and examples for simulating different anatomical poses and body morphologies (e.g., body-mass indexes) from volumetric, voxelized, anatomical models. In particular, we propose to adapt real-time surgical simulation methods to serve as the underlying methods in changing the pose and the fat/muscle composition of anatomic models used in specific absorption ratio (SAR) studies. This approach has the key benefit of being able to generate morphed voxelized anatomical models for SAR computations in less than 10 minutes. Intuitive software applications that incorporate these algorithms are already being prototyped and will be extended, evaluated, and delivered in Phase 1. This proposal builds upon significant prior work at Kitware and makes use of several open-source, image-processing toolkits. The product will be offered as open-source software and used to attract additional consulting clients to Kitware. BENEFIT: In military applications, directed energy is both a threat to military personnel as well as a possible weapon to be used against opposing forces. The modern battlefield is potentially rife with electromagnetic (EM) radiation, whether directly from EM weapons, or more frequently as the indirect result of explosions or weapon discharges. Hence it is important to understand the effects of EM on personnel effectiveness, and to find ways to shield against deleterious effects. Alternatively, directed energy can be harnessed in a variety of ways including the creation of non-lethal weapons to disorient and/or disable opposing forces. In medicine, directed x-ray energy is a dominant tool for cancer treatment. New treatments that exploit focused ultrasound, radio-frequency, and microwave energies are also being investigated. In commerce, there is an even more diverse range of applications that consider the interaction of energy and anatomy. For example, OSHA standards on electro-magnetic field (EMF) and extremely low frequency emissions (ELF) influence hair dryer design as well as power-line placement. Cell-phones are scrutinized using measures of radiation absorption. Laser pointers, police traffic radars, and microwave ovens must also be designed using models of the tissues energy absorption properties. Thus there are a wide variety of applications that require understanding directed energy and its effects on the human body. Empirical research on animals and phantom models are two approaches to such directed energy studies. Another important approach is to use numerical simulation techniques. Numeric simulations are a preferred approach to directed energy research in many cases. Compared to other approaches to energy absorption research, numeric simulations are generally cheaper, do not endanger animals or humans, and can be adapted to circumstances that are difficult to replicate in an experimental setting. Numeric simulations use volumetric models, differential equations, and Monte Carlo methods to predict the expected effect of energy on anatomy. For example, finite difference time domain calculations can be performed to investigate the frequency dependence of the SAR of a voxelized model of the human body. Full and partial body resonance conditions can be computed for grounded and ungrounded conditions and with the subject in different poses. This proposal is concerned with forming anatomical models from medical images in order to facilitate the use of numerical simulation for directed energy research. It moves beyond existing standards that employ static models and a limited number of models by allowing models derived from medical images to be (a) re-posed so as to simulate a range of conditions and (b) morphed into different anatomic body types (e.g., to have different fat and muscle volumes and to have organs of different volumes) so as to simulate a larger number of different individuals. The Society of Nuclear Medicine and numerous other agencies have multiple publications on how pose and body composition can effect SAR measures throughout the body, e.g., Marine et al."Changes in Radiation Dose with Variations in Human Anatomy: Larger and Smaller Normal-Stature Adults"The Journal of Nuclear Medicine, 51(5):806-11, 2010.