Bright light therapy is a treatment modality for seasonal affective disorder and circadian rhythm disorders in which artificial light of 2,500 lux or higher at the eye is effective. Although short-wavelength visible light is more effective than long-wavelength visible light, it may be hazardous to the retina. Recently, light-emitting diodes (LEDs) have been used as the light source in bright light therapy apparatuses. We developed goggles for bright light therapy equipped with LEDs as the light source. The aim of this study was to examine the efficacy and safety of our goggles when emitting 10,000-lux light with its short-wavelength light content reduced by 30% or 50% (denoted as 30%-cut and 50%-cut light, respectively, henceforth). Six healthy young males participated in this study. They were administered no light, 50%-cut light, and 30%-cut light for 30 min early in the morning for 4 days each. Subjective sleepiness and sleep quality were evaluated by the Stanford Sleepiness Scale (SSS) and the Oguri–Shirakawa–Azumi sleep inventory MA version (OSA-MA), respectively. Subjective sleepiness evaluated by the SSS and the subscale of the OSA-MA significantly decreased with 30%-cut light compared with no light. Psychomotor performance evaluated by a calculation task improved with the 30%-cut light, although not significant after multiple comparisons were considered. No abnormality was found by ophthalmoscopy and the vision test. In conclusion, our goggles with 30%-cut light may be safe and have an awakening effect.

We have recently developed a portable light therapy apparatus for improvement of sleep quality and wakefulness. This technical note presents some preliminary experiments useful for design and evaluation of portable light therapy apparatus.

An electro-larynx is one of speech-substitute devices for patients who have lost laryngeal function. Unfortunately, the voices produced by a conventional electro-larynx are completely flat, unlike a human voice. In order to improve it, we developed a pitch-controlled electro-larynx that allows patients to control a voice intonation using their exhalation. The pitch-controlled electro-larynx has been manufactured in Japan and about 3500 patients have used the device since 1998. However, most patients have strongly requested a further advanced electro-larynx so that they can use it without their hands occupied. We designed a wearable electro-larynx so that it contributes to increase their quality of life. The new electro-larynx can be attached to the patient's neck using a thermo-plastic brace on which a thin-vibrator can be mounted. In this report, we mentioned how to design the wearable electro-larynx and the new electro-larynx was evaluated from a view-point of its sound quality and the usability. Although our wearable electro-larynx has not yet been equipped with the pitch-control function, it was ascertained that it works well while the users are moving their head in the various direction.

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An electrolarynx is a useful speech-substitute device for patients who have lost laryngeal function. Unfortunately, the voices produced by a conventional electrolarynx are completely flat, unlike a human voice. For that reason, we developed a pitch-controlled electrolarynx that allows patients to control a voice intonation using their exhalation [N. Uemi and T. Ifukube, ‘‘Design of a new electrolarynx having a pitch control function,’’ IEEE RO-MAN’94, 198–203 (1994)]. This pitch-controlled electrolarynx has been manufactured and more than 3000 patients have used the device since 1998. However, many patients have strongly requested that we design a hands-free electrolarynx so that they can perform daily life functions and work in their office without their hands occupied by the electrolarynx control during use. In response to that request, we designed some models of a hands-free electrolarynx that is attachable to the patient’s neck. Furthermore, by comparing the models based on evaluation tests regarding its sound quality and usability, a thermo-plastic brace was found to be the best for attachment to the neck. Although our hands-free electrolarynx has not yet been equipped with the pitch-control function, it was ascertained that it is useful for taking notes while talking on the phone, and so on.