Gifu University of Medical Science

About: Gifu University of Medical Science is a education organization based out in Gifu City, Japan. It is known for research contribution in the topics: Imaging phantom & Motion sickness. The organization has 89 authors who have published 202 publications receiving 1350 citations.

Anatomo-functional basis of restless legs syndrome

Abstract: Restless legs syndrome (RLS) is a common sensory-motor disorder characterized by a variety of uncomfortable sensations associated with an urge to move the legs, relief with movement, strong circadian modulation, and often occurring at sleep onset, impairing sleep quality and inducing insomnia and reduced quality of life. RLS often responds to dopaminergic treatment, but over time, augmentation develops. Some additional key features of the disorder include greater somatotrophic spread when severe or with augmentation, painful sensations, and an association with brain iron deficiency. These features across neurophysiologic subsystems suggest a neural network disorder.

Experimental study on control of visually evoked postural responses by galvanic vestibular stimulation

Abstract: Visually evoked postural responses (VEPRs) are physiological responses to perceived motion that are related to visually induced motion sickness (VIMS). We considered that VEPRs are just a conflict correction response aimed at matching information from the senses of vision and equilibrium. We also believe that understanding the consequences of suppression or acceleration of VEPRs may elucidate the pathogenic mechanism of VIMS and help establish methods for preventing VIMS. Our group has developed a system combining digital imagery and galvanic vestibular stimulation (GVS) to manipulate VEPRs. In this study, we attempted to verify a method of extrinsically controlling VEPRs. We determined the GVS current values that induced loss of motion sensation in subjects watching moving objects, measured body sway under different movie speed and GVS-off or on conditions, and tested whether GVS could counteract VEPRs. The results clearly showed that 1) the GVS current value increased along with increased motion speed observed in a video, and 2) it was possible to control VEPRs by GVS. However, it was difficult to completely control VEPRs by GVS, possibly because characteristics of posture can change based on the allocation of consciousness.

Design of a noise-dependent shrinkage function in wavelet shrinkage of X-ray CT image

Abstract: Many shrinkage functions have been introduced and applied for the wavelet shrinkage denoising of computed tomography (CT) images. However, these functions have problems in continuity of functions and cause “shrinkage artifacts”. Therefore, we designed a new and smooth shrinkage function using noise distribution. The proposed shrinkage function was designed under the following four conditions: (1) use of noise distribution, (2) shrunk coefficients having all ranges of amplitude, (3) function continuity, and (4) property of a function that is controllable by two parameters. The designed function was applied to phantom and chest CT images and denoising performance was compared with other functions. In the proposed method, edge and pixel values were maintained when compared with previous functions, the occurrence of shrinkage artifacts was smaller, and high- quality denoised images were obtained. The proposed shrinkage function is effective for low-dose noisy CT images when using accurately selected parameters.

Mobility of an elastic glove for extravehicular activity without prebreathing.

Abstract: Introduction The current US extravehicular activity (EVA) suit is pressurized at 029 atm, which is much lower than the pressures of sea level and inside a space station Higher pressure can reduce the risk of decompression sickness (DCS), but mobility would be sacrificed We have demonstrated that a glove and sleeve made of elastic material increased mobility when compared with those made of nonelastic material, such as that found in the current suit We hypothesized that an elastic glove of 065 atm that has no risk of DCS also has greater mobility compared with a non-elastic glove of 029 atm Methods The right hands of 10 healthy volunteers were studied in a chamber with their bare hands at normal ambient pressure, after donning a non-elastic glove with a pressure differential of 029 atm, and after donning an elastic glove with a pressure differential of 029 and 065 atm Range of motion (ROM) of the index finger and surface electromyography (EMG) amplitudes during finger flexion were measured Results ROM with gloves was significantly smaller than that of bare hands, but was similar between conditions of gloves regardless of elasticity and pressure differentials However, EMG amplitudes with the elastic glove of 029 and 065 atm were significantly smaller than those with the non-elastic glove of 029 atm Discussion The results suggest that mobility of the elastic glove of 065 atm may be better than that of the non-elastic glove of 029 atm, similar to that used in the current EVA suit

Verification of nonlinearity in digital X-ray images using surrogate method

Abstract: We investigate the nonlinearity in digital X-ray images to determine the feasibility of a noise reduction process using a mathematical model, which realizes an accurate digital X-ray imaging system To develop this mathematical model, it is important to confirm whether the system is linear or nonlinear We have verified the nonlinearity of the imaging system through an analysis of computed radiography (CR) images by using the method of surrogate, a statistical test of nonlinearity, and the Wayland test In the method of surrogate, we use the Fourier transform surrogate method The Wayland test can be used for evaluating the complexity of the orbit of a signal aggregate called the attractor reconstructed in a high-dimensional phase space using a nonlinear statistical parameter called the translation error Nonlinearity is determined by statistically comparing the translation error of the original data with that of the surrogate data X-ray images are obtained under different conditions to investigate the effects of various tube voltages—50 and 80 kV—and dose settings—2 and 10 mAs We extract 30 profiles from both directions, the directions vertical (V-direction) and horizontal (H-direction) to the X-ray tube In the H-direction, nonlinearity is found at all voltage and dose settings On the other hand, nonlinearity is found only at 10 mAs and 80 kV in the V-direction Hence, it can be concluded that nonlinearity is indicated by a decrease in the quantum mottle, and the factors of nonlinearity exhibit the comprehensive variation produced by the digital X-ray imaging system