Fast and Robust Capacitive Imaging of Cylindrical Non-Metallic Media

In this paper, a unique approach to the imaging of non-metallic media using capacitive sensing is presented. By using customized sensor plates in single-ended and differential configurations, responses to hidden objects can be captured over a cylindrical aperture surrounding the inspected medium. Then, by processing the acquired data using a novel imaging technique based on the convolution theory, Fourier and inverse Fourier transforms, and exact low resolution electromagnetic tomography (eLORETA), images are reconstructed over multiple radial depths using the acquired sensor data. Imaging hidden objects over multiple depths has wide range of applications, from biomedical imaging to nondestructive testing of the materials. Performance of the proposed imaging technique is demonstrated via experimental results.

rTMS and Suicidality in Adulthood; An Exploratory Open-Labeled Neuromodulative Approach to Battle Suicide

Background: Suicidal attempts are one of the most critical issues with a huge burden on family and health systems all around the world. To decrease the hazardous outcomes of this issue, mental health systems are trying to apply the most effective and safe interventions. In this regard, repetitive Transcranial Magnetic Stimulation (rTMS ) as a non-invasive approach could be a proper treatment approach. We investigated the impact of rTMS method on the treatment of the patients with suicidal ideation. For this purpose, the application of rTMS when integrating with Low-Resolution Electromagnetic Tomography (LORETA) data has been assessed.Methods: As an open-labeled study we enrolled 7 adult men who were recently rescued from suicidal attempts and referred to our psychiatric clinic for three consecutive months (2018). The severity of suicidal ideation was measured by the Beck Scale of Suicidal Ideation (SSI) and brain activity via Low-Resolution Electromagnetic Tomography (LORETA), administered at baseline and the end of the treatment course. Repetitive TMS was delivered to the left and right dorsolateral prefrontal cortices (DLPFC) with a figure-eight solid core coil at 110% motor threshold, 10 Hertz (Hz) and 4 second (s) train duration, (3000 pulses) (total 12 sessions; 36,000 stimuli). Six sessions daily and six sessions within two weeks were scheduled.Results: According to the results of psychiatric re-interview, LORETA, and SSI scores of all patients revealed an impressive and statistically significant decrease in suicidal ideation. No side effects were seen during the treatment course.Conclusions: Scheduled three consecutive weeks rTMS course was significantly effective in remitting acute suicidal ideation in adult men regardless of psychiatric diagnosis. Larger double-blinded studies must be conducted to validate the clinical usage of this safe and non-invasive treatment approach in the area of psychiatry.

Impact of Biofeedback Interventions on Driving Performance in Individuals with Persistent Post-Concussive Symptoms

Low resolution electromagnetic tomography (LoRETA) neurofeedback and heart rate variability (HRV) biofeedback may improve driving ability by enhancing attention, impulse control, and peripheral vision, and reducing stress. However, it is unclear whether combined LoRETA neurofeedback and HRV biofeedback can improve driving performance for individuals experiencing persistent post-concussive symptoms (PPCS). In this study, seven individuals with PPCS completed an eight-week LoRETA neurofeedback and HRV biofeedback intervention. Changes in participants’ simulated driving performance and self-reported symptoms were measured and compared to two control groups: individuals with PPCS (n = 9), and healthy control participants (n = 8). Individuals in the intervention and PPCS control groups reported reduced PPCS severity (p < .05) compared to healthy control participants. Interestingly, individuals in the intervention group responded variably. These results indicate that more research is necessary to identify the subgroup of individuals that respond to LoRETA neurofeedback and HRV biofeedback and confirm these preliminary results.

Electrical Source Imaging in Freely Moving Rats: Evaluation of a 12-Electrode Cortical Electroencephalography System

This work presents and evaluates a 12-electrode intracranial electroencephalography system developed at the National Institute of Mental Health (Klecany, Czech Republic) in terms of an electrical source imaging (ESI) technique in rats. The electrode system was originally designed for translational research purposes. This study demonstrates that it is also possible to use this well-established system for ESI, and estimates its precision, accuracy, and limitations. Furthermore, this paper sets a methodological basis for future implants. Source localization quality is evaluated using three approaches based on surrogate data, physical phantom measurements, and in vivo experiments. The forward model for source localization is obtained from the FieldTrip-SimBio pipeline using the finite-element method. Rat brain tissue extracted from a magnetic resonance imaging template is approximated by a single-compartment homogeneous tetrahedral head model. Four inverse solvers were tested: standardized low-resolution brain electromagnetic tomography, exact low-resolution brain electromagnetic tomography (eLORETA), linear constrained minimum variance (LCMV), and dynamic imaging of coherent sources. Based on surrogate data, this paper evaluates the accuracy and precision of all solvers within the brain volume using error distance and reliability maps. The mean error distance over the whole brain was found to be the lowest in the eLORETA solution through signal to noise ratios (SNRs) (0.2 mm for 25 dB SNR). The LCMV outperformed eLORETA under higher SNR conditions, and exhibiting higher spatial precision. Both of these inverse solvers provided accurate results in a phantom experiment (1.6 mm mean error distance across shallow and 2.6 mm across subcortical testing dipoles). Utilizing the developed technique in freely moving rats, an auditory steady-state response experiment provided results in line with previously reported findings. The obtained results support the idea of utilizing a 12-electrode system for ESI and using it as a solid basis for the development of future ESI dedicated implants.