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.

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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.

Auditory hypersensitivity in autism is frequently observed in clinics. Dysfunction in the auditory brainstem has been suspected. We have established autism model rats using prenatal thalidomide exposure. Here we investigated whether abnormal response occurs in the brainstem following sound stimulus in autism model rats. Autism model rats were prepared by prenatal exposure to thalidomide on embryonic days 9 and 10 in pregnant rats. Then, the animals were exposed to 16‐kHz pure tone auditory stimulus and c‐Fos immunostaining was performed to examine the neuronal activity on postnatal day 49 to 51. Following sound stimulus, increased number of c‐Fos‐positive neurons was observed in the medial nucleus of the trapezoid body of autism model rats compared with the control rats. These results suggest that prenatal thalidomide might cause altered processing of auditory stimulus, leading to the characteristics of auditory hypersensitivity in autism.

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.