Image-guided surgery systems are often used to provide surgeons with informational support. Due to several unique advantages such as ease of use, real-time image acquisition, and no ionizing radiation, ultrasound is a common medical imaging modality used in image-guided surgery systems. To perform advanced forms of guidance with ultrasound, such as virtual image overlays or automated robotic ac...

An accurate and fast radiation dose calculation is essential for successful radiation radiotherapy. The aim of this study was to implement a new graphic processing unit (GPU) based radiation therapy treatment planning for accurate and fast dose calculation in radiotherapy centers. A program was written for parallel running based on GPU. The code validation was performed by EGSnrc/DOSXYZnrc. Mor...

Background: In nuclear medicine application often it is required to use computational methods for evaluation of organ absorbed dose. Monte Carlo simulation and phantoms have been used in many works before. The shape, size and volume in organs are varied, and this variation will produce error in dose calculation if no correction is applied. Materials and Methods: A computational framewo...

This paper presents a novel teleoperation scheme to control a PUMA robotic manipulator with a Phantom haptic device. Using local force control at the slave robot, contact with soft and hard surfaces is attained with high performance. The control design inserts a virtual spring between the master and slave control systems to generate the desired forces. The closed loop performance is increased b...

Relation between position resolution of haptic device and stability problem is discussed in this paper. Based on virtual wall model and passive characteristics of contact interaction, violation of passive dynamic criteria and energy accumulation of motor output are proved to be the factors that influence system stability. Influence of device parameter on stability is discussed and the criterion...

We present the theory and some applications of the synthetic aperture focusing technique applied to single transducer ultrasonic data sets. In this technique a virtual source located at the geometrical focal point of the physical transducer is algorithmically generated and thus allows for tighter focusing over a geometrically larger scan volume. We present results from a structural test phantom...

PURPOSE To investigate beam quality correction, KQQ0 (r) and phantom scatter correction, Kphan (r) for lithium formate dosimeter as a function of distance r along the transverse axis of the high-energy brachytherapy sources 60Co, 137Cs, 192Ir and 169Yb using the Monte Carlo-based EGSnrc code system. MATERIALS AND METHODS The brachytherapy sources investigated in this study are BEBIG High Dose...

This paper presents an initial implementation of a Virtual Ultrasound Imaging System as an interactive educational tool for students and researchers in the medical ultrasound imaging field. The system uses a cause and effect approach for understanding the results of changing transducer attributes and pulse parameters on the quality of the ultrasound image. The elements of the system include Fie...

In respect of imaging quality and patient safety, temperature rises and SAR distributions, which are caused by interaction of the applied electromagnetic fields during MR exams, are of high interest for implants in MR tomography [1]. High local SAR values are equivalent to high local temperature increases [2]. For developing support for radio frequency (RF) induced heating experiments, SAR valu...