Yuichi Noro

Novel acoustic evaluation system for scratching behavior in itching dermatitis: Rapid and accurate analysis for nocturnal scratching of atopic dermatitis patients

Quantitative analysis of itching in patients with itching dermatitis including atopic dermatitis (AD) is indispensable for the evaluation of disease activity and response to therapy. However, the objective evaluation system for itching is limited. We have developed a new objective and quantitative scratching behavior detection system using a wristwatch‐type sound detector. The scratch sound detected on the wrist is recorded on a personal computer through a filtering, squaring and smoothing process by specific hardware. Subsequently, the data is automatically processed and judged for the scratching movement using specific software based on the periodicity and energy of the signal. Twenty‐four measurements for healthy volunteers and those with AD by this system were evaluated by comparison with a simultaneously recorded video analysis system. The ratio of scratching time in sleeping time evaluated by these two systems was almost identical. The healthy subjects scratched their skin approximately 2 min during 6 h of sleeping time, while the mean scratching time of AD subjects was 24 min in their sleeping time. In contrast to the time‐consuming video analysis system, this system takes only several minutes for evaluation of an overnight record. This scratch sound detection system is expected to serve as a new objective evaluation tool for itching dermatitis, namely, AD, and development of anti‐itch therapies for dermatitis.

Olopatadine, a non‐sedating H1 antihistamine, decreases the nocturnal scratching without affecting sleep quality in atopic dermatitis

We have demonstrated for the first time that a second‐generation antihistamine ameliorates nocturnal scratching behavior in atopic dermatitis patients using a modified wristwatch‐type acoustic scratching counting system that we have recently developed. We also analyzed the sleep quality by simultaneous recording of electroencephalogram, and found that sleep quality was unaffected.

Study on Transmission Characteristics of Transformers of a RF Splitter

In this paper, we report on the transmission characteristics of transformers of a RF splitter widely used in CATV systems. From the point of view of broadening the splitters operating frequency, the relationship between the RF transformers transmission characteristics and design parameters has been investigated using computer-aided engineering. Based on the calculations, a sample device has been fabricated to confirm the theoretical results. It has been found that the configulation of the transformer winding is the most important factor affecting device performance. By selecting the appropriate winding, excessive loss can be suppressed to less than 1.6 dB and 3 dB in a frequency range of 20 MHz to 2,600 MHz for the cases of 2-way and 4-way splitters, respectively.

Adaptive Compensation Method for the Temperature Dependence of RF Transformer Isolation

In this study, we propose an adaptive compensation method for the temperature dependence of RF transformer isolation and present results of preliminary experiments. First of all, we examine the isolation temperature dependence of an RF transformer designed as a splitter, by means of both an electromagnetic simulation technique and experiments, to show the significance of the present issue. Then, we discuss the nature of a transformer core so as to obtain the most desirable isolation characteristics against a temperature change. Finally, in order to adaptively compensate for the isolation variation due to temperature, we propose a bias current superimposed on the RF signal, where the current amplitude is adjusted according to temperature change, and demonstrate the results of preliminary experiments conducted at a fixed temperature, but with different bias currents, indicating the validity of the proposed method.

Optical Evaluation System for a Seaweed-Water Mixture in a Seaweed Processing Plant

An in-process optical measurement system has been proposed for a seaweed-water mixture in a seaweed processing plant with the aim of quality evaluation of final products. The system or method is based on the assumption that the optical transmissions of the mixture at particular wavelengths could be related to seaweed-product quality. In order to ascertain the above expectation, we have made measurements in a plant and done some analysis, including principal component analysis, on the measurement data. The results imply that the optical transmission data of the mixture can be used to estimate the quality of the final seaweed products. The information obtained could also be useful in making a feedback control of the process for producing better products.

Simplified Method of Measuring Magnetic Permeability Temperature Profile for RF Device Applications

Ferrite is popular as a core material for RF transformers. Since transmission characteristics of RF transformers are affected by the core’s permeability, which has a large temperature dependence, the development of a method for measuring the core permeability temperature profile is important. In this study, a temperature profile measurement of ferrite core permeability has been investigated using a microstrip line method which has the advantage of the circuit being compact in size and therefore suitable for measuring temperature profiles. Based on the results measured with a sample ferrite core, the temperature dependence of RF transformer performance (isolation) is also discussed. Furthermore, basic results of experiments to compensate for the degradation in isolation is presented.

Development of a Super Broadband RF Splitter Using Bead Type Ferrite Core Transformers

We report on the broadening of the operating frequency of a RF splitter widely used in CATV systems. In order to realize this, the relationship between the splitter’s transmission characteristics and design parameters has been investigated using computer-aided engineering. Based on the calculations, a sample device has been fabricated to confirm the theoretical results. It has been found that by selecting the parameters appropriately, excessive loss can be suppressed to less than 1.6dB and 3dB in a frequency range of 20MHz to 2,600MHz in the cases of 2-way and 4-way splitters, respectively.