Effects of inaudible binaural beats on visuospatial memory.

Objectives: Binaural beats are auditory beat stimulation that produces sounds and induces a specific state of brain wave based on the difference in the frequency of stimulation. This study aimed to investigate the effects of inaudible binaural beats on visuospatial memory at 18 000 Hz reference and 10 Hz difference frequencies.

Methods: Eighteen adult subjects in their twenties were enrolled, including 12 males (mean age: 23.

Effect of binaural beat in the inaudible band on EEG (STROBE).

This study aimed to determine the effects of the binaural beat (BB) on brainwave induction using an inaudible baseline frequency outside the audible frequency range. Experiments were conducted on 18 subjects (11 males [mean age: 25.7 ± 1.

Effective Connectivity Analysis of Brain Activated Regions during Distracted Driving.

This study aims to use functional magnetic resonance imaging (fMRI) to assess the effective connectivity between the regions of the brain activated when driving and performing a secondary task (addition task). The subjects used an MR-compatible driving simulator ㅊ to manipulate the driving wheel with both hands and control the pedals (accelerator and brake) with their right foot as if they were driving in an actual environment. Effective connectivity analysis was performed for three regions of the right and the left hemispheres with the highest z-scores, and six of the regions of the entire brain (right and left hemisphere) activated during driving by dynamic causal modeling (DCM).

A simple segmentation and quantification method for numerical quantitative analysis of cells and tissues.

Background: Microscopic image analysis based on image processing is required for quantitative evaluation of decellularization. Existing methods are not widely used because of expensive commercial software, and machine learning-based techniques lack generality for decellularization because many high-resolution image data has to be processed.

Objective: In this study, we developed an image processing algorithm for quantitative analysis of tissues and cells in a general microscopic image.

A simple method for removing initial irregularity of an electrocardiogram during a transient state of a power supply in a defibrillator.

Background: The defibrillator is a device that instantaneously discharges the high energy stored in the capacitor to the human body to help revitalize the heart. The circuit for charging the capacitor uses the same power source as the biosignal measurement unit. Therefore, variation in main power supply voltage, ground noise, and electromagnetic interference from the charging circuit can induce distortion into the biosignal at the initial stage of charging.

Unravelling interrelations between chemical composition and refractive index dispersion of infrared-transmitting chalcogenide glasses.

A facile procedure for compositional screening of chalcogenide glass (CG) is proposed to manage its infrared transmission edge (ω) as well as refractive index dispersion (ν) in the long-wavelength infrared (LWIR) range. Both ω and ν of CG turn out to be interpretable simply in connection with its chemical composition based on a postulation that CG behaves as a single average harmonic oscillator (SAHO). In this SAHO model, ω is expressed as a function of molar mass and average bond energy, both of which are easily accessible for a given CG composition.

Histological and Mathematical Analysis of the Irreversibly Electroporated Liver Tissue.

Irreversible electroporation has clinically been used to treat various types of cancer. A plan on how to apply irreversible electroporation before practicing is very important to increase the ablation area and reduce the side effects. Several electrical models have been developed to predict the ablation area with applied electric energy.

Change of neuronal activations induced by the passive perception of driving speed difference.

The change of neuronal activation due to the passive perception of various driving speeds in comparison to a reference driving speed was assessed using functional Magnetic Resonance Imaging. Videos recorded in real driving conditions on the road at driving speeds of 50, 70, 90, and 110 km/h were shown as visual stimuli. An experiment consisted of three blocks, each having a control phase (50km/h) and a stimulation phase (70, 90, or 110 km/h).

Development of a simultaneous vibration and pressure stimulation system for cognitive studies.

In this study, a tactile stimulator that could separately or simultaneously display the vibrotactile and pressure sense was developed. The developed system consisted of a control unit, a drive unit, and an actuator, and can be operated with PC or manually. This system quantitatively controls the stimulation parameters such as the stimulation intensity, duration, frequency, and stimulation type.

Response time of visual matching task and heart rate in children with Attention Deficit Hyperactivity Disorder (ADHD).

The purpose of this study was to investigate the relation between response time of visual matching task and heart rate (HR) in children with Attention Deficit Hyperactivity Disorder (ADHD). Thirty boys who were diagnosed with ADHD and are under treatment participated in the study. The experiment consisted of three phases, a total of 5 min with rest phase, control phase, and visual matching task phase.

Effects of three levels of arousal on 3-back working memory task performance.

This study investigated how three levels of arousal affected performance of a 3-back working memory task. Ten female and ten male university students participated in this experiment. With pictures selected from a group test, three levels of arousal were induced--i.

Development of a simple pressure and heat stimulator for intra- and interdigit functional magnetic resonance imaging.

For this study, we developed a simple pressure and heat stimulator that can quantitatively control pressure and provide heat stimulation to intra- and interdigit areas. The developed stimulator consists of a control unit, drive units, and tactors. The control unit controls the stimulation parameters, such as stimulation types, intensity, time, and channel, and transmits a created signal of stimulation to the drive units.

Changes of apoptosis in tumor tissues with time after irreversible electroporation.

Irreversible electroporation is a novel method of ablating living tissues through its non-thermal effects, unlike radiofrequency ablation which has a severe problem of heat sink. It is due to high-energy direct current which leads to permanent disruption of lipid bilayer integrity in terms of exchanges between intra- and extracellular components via nano-sized pores. That finally causes irreversible damage to cellular homeostasis.

Changes in simple visual matching task performance and physiological signals in intellectually and developmentally disabled people due to administration of highly concentrated oxygen.

Background: This study attempted to identify the effect of administration of highly concentrated oxygen on simple visual matching task performance, blood oxygen saturation [SpO2 (%)], and heart rate [HR (bpm)] of intellectually and developmentally disabled people.

Methods: Nineteen intellectually and developmentally disabled people (mean age 30.6 ± 5.

Development of a simple MR-compatible vibrotactile stimulator using a planar-coil-type actuator.

For this study, we developed a magnetic resonance (MR)-compatible vibrotactile stimulator using a planar-coil-type actuator. The newly developed vibrotactile stimulator consists of three units: control unit, drive unit, and planar-coil-type actuator. The control unit controls frequency, intensity, time, and channel, and transfers the stimulation signals to the drive unit.

Correlation between cognitive ability measured by response time of 1-back task and changes of SpO2 by supplying three different levels of oxygen in the elderly.

Aim: This study investigated the correlation between response time of the 1-back task and changes of blood oxygen saturation (SpO2 ) by supplying three different levels of oxygen (21%, 1 L/min; 93%, 1 L/min; 93%, 5 L/min) in the elderly.

Methods: A total of 17 older adults (mean age 72.9 ± 4.

Changes of 2-back task performance and physiological signals in ADHD children due to transient increase in oxygen level.

This study investigated the effect of 92% oxygen administration on 2-back task performance, blood oxygen saturation (SpO(2) [%]), and heart rate (HR [bpm]) of Attention Deficit Hyperactivity Disorder (ADHD) children. Subjects were thirteen boys (mean 12.9±1.

Development of a tactile stimulator with simultaneous visual and auditory stimulation using E-Prime software.

In this study, a tactile stimulator was developed, which can stimulate visual and auditory senses simultaneously by using the E-Prime software. This study tried to compensate for systematic stimulation control and other problems that occurred with previously developed tactile stimulators. The newly developed system consists of three units: a control unit, a drive unit and a vibrator.

A simple 5-DoF MR-compatible motion signal measurement system.

The purpose of this study was to develop a simple motion measurement system with magnetic resonance (MR) compatibility and safety. The motion measurement system proposed here can measure 5-DoF motion signals without deteriorating the MR images, and it has no effect on the intense and homogeneous main magnetic field, the temporal-gradient magnetic field (which varies rapidly with time), the transceiver radio frequency (RF) coil, and the RF pulse during MR data acquisition. A three-axis accelerometer and a two-axis gyroscope were used to measure 5-DoF motion signals, and Velcro was used to attach a sensor module to a finger or wrist.

Preclinical analysis of irreversible electroporation on rat liver tissues using a microfabricated electroporator.

A microfabricated electroporator (MFE) for the irreversible electroporation (IRE) of tissues has been developed by miniaturizing a clinical electroporator with a two-needle array while keeping the same electric field strength distribution. Since IRE was brought to special attention as one of the local tissue ablation techniques to treat tumors, many preclinical studies have been conducted to investigate the efficacy of IRE on animal tissues. However, some technical difficulties have been frequently encountered due to the macroscale dimension of clinical electroporators, particularly in experiments on small animal models such as the mouse or rat.

Activation of the limbic system under 30% oxygen during a visuospatial task: an fMRI study.

The purpose of this study was to observe activation of the limbic system during the performance of visuospatial tasks under 21% O(2) or 30% O(2). Eight right-handed male college students were selected as subjects for this study. A visuospatial task was presented while brain images were scanned by a 3T fMRI system.

Development of a magnetic resonance-compatible galvanic skin response measurement system using optic signal.

The purpose of the current study is to develop a magnetic resonance (MR)-compatible galvanic skin response (GSR) measurement system that can measure the GSR signal during MR image acquisition. If GSR signals are measured simultaneously with the acquisition of MR images, there can be a mutual interference effect. The present system was designed to block noises caused by the main magnetic field, the gradient magnetic field, and the radio frequency (RF) pulse when MR images are acquired.