Tim P. DeMonte

Learn More
Although defibrillation has been in clinical use for more than 50 years, the complete current flow distribution inside the body during a defibrillation procedure has never been directly measured. This is due to the lack of appropriate imaging technology to noninvasively monitor the current flow inside the body. The current density imaging (CDI) technique,(More)
The origin of electrical burns under gel-type surface electrodes is a controversial topic that is not well understood. To investigate the phenomenon, we have developed an excised porcine skin-gel model, and used low-frequency current density imaging (LFCDI) to determine the current density (CD) distribution through the skin before and after burns were(More)
Radio-frequency current density imaging (RF-CDI) is an imaging technique that noninvasively measures current density distribution at the Larmor frequency utilizing magnetic resonance imaging (MRI). Previously implemented RF-CDI techniques were only able to image a single slice transverse to the static magnetic field B(0) . This paper describes the first(More)
Current density imaging (CDI) is a technique that uses magnetic resonance imaging (MRI) to measure the distribution of externally applied electric current inside tissues. However, GDI processing is rendered inaccurate by the distortion caused by the nonlinearity of MRI gradient fields. The distortion interferes with the proper registration and the curl(More)
The origin of electrical burns under gel-type surface electrodes is a controversial topic that is not well understood. To investigate the phenomenon, we have developed an excised porcine skin+gel model. In the present paper, we describe methods to detect these burns in the skin+gel model in an effort to understand the genesis of these burns. Burns were(More)
Radio frequency current density imaging (RF-CDI) is an imaging technique that measures current density distribution at the Larmor frequency utilizing magnetic resonance imaging (MRI). The multi-slice RF-CDI sequence has extended the ability of RF-CDI to image multiple slices and thus has enhanced its capacity for biomedical applications. In this paper, the(More)
Current density imaging (CDI) is a magnetic resonance imaging (MRI) technique used to quantitatively measure current density vectors throughout the volume of an object/subject placed in the MRI system. Electrical current pulses are applied externally to the object/subject and are synchronized with the MRI sequence. In this work, CDI is used to measure(More)
We present a quantitative validation study to assess the accuracy of low-frequency conductivity imaging methods, based on a testing current measured using Current Density Imaging (CDI). We tested the proposed procedure to study the influence of tissue anisotropy on the accuracy of conductivity reconstruction methods, using a finite element model of(More)
Polar Decomposition Radio-frequency Current Density Imaging (PD-RFCDI) is an imaging technique that non-invasively measures RF current density components inside a sample using MRI. Previous PD-RFCDI implementations suffer from the strict constraint on the amount of applied current as well as severe interference from the unwanted induced current. This work(More)
INTRODUCTION: Automatic External Defibrillator (AED) electrodes are flexible surface electrodes used to administer emergency defibrillation procedures. The electrodes used in this study have an elliptical shape with the ends of the long axis cutoff, as in fig. 1. Dimensions of the electrodes used in this study are 13.3 cm x 8.7 cm. A standard AED electrode(More)