Kenji Taira

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Optical frequency domain imaging (OFDI) in the 800-nm biological imaging window is demonstrated by using a novel wavelength-swept laser source. The laser output is tuned continuously from 815 to 870 nm at a 43.2-kHz repetition rate with 7-mW average power. Axial resolution of 10-μm in biological tissue and peak sensitivity of 96 dB are achieved. In vivo(More)
A total of 788 people (aged from 60 to 93 years) living in the Okinawa prefecture, renowned for the long life expectancy of its citizens, were randomly chosen as subjects. A questionnaire based on lifestyle and sleep-health was distributed. Following this, subjects were chosen in groups of nine from the good sleep-health group and then from the poor(More)
A survey was made of the sleep and lifestyle activity patterns of 3754 students from 14 different junior high schools on Okinawa Island. The survey showed that bedtimes became progressively and significantly later as students ascended to higher grades, resulting in adolescent sleep debt. The later adolescents retired to sleep, there appeared significantly(More)
The purpose of the present study was to examine the effects of short nap and exercise on the sleep quality of elderly people who reported difficulty in sleeping. 'Interventions' such as short nap after lunch and moderate-intensity exercise in the evening were carried out for 4 weeks. After the 'interventions', wake time after sleep onset significantly(More)
We demonstrate a frequency comb (FC) swept laser and a frequency comb Fourier domain mode locked (FC-FDML) laser for applications in optical coherence tomography (OCT). The fiber-based FC swept lasers operate at a sweep rate of 1kHz and 120kHz, respectively over a 135nm tuning range centered at 1310nm with average output powers of 50mW. A 25GHz free(More)
In three-dimensional television (3D TV) broadcasting, we find the effect of fundamental depth resolution and the cardboard effect to the perceived depth resolution on multi-view display is important. The observer distance and the specification of multi-view display quantize the expressible depth range, which affect the perception of depth resolution of the(More)
Since 1996, a hybrid experiment consisting of the emulsion chamber and burst detector array and the Tibet-II air-shower array has been operated at Yangbajing (4300 m above sea level, 606 g/cm 2) in Tibet. This experiment can detect air-shower cores, called as burst events, accompanied by air showers in excess of about 100 TeV. We observed about 4300 burst(More)
Optical coherence tomography (OCT) is an emerging diagnostic technology, developed by our research group and collaborators in 1991 [1], and it has been investigated for applications in several medical fields [2]. OCT enables the visualization of tissue microstructure in situ and in real time with resolutions in the 1-10 µm range, and previous studies have(More)
Optical frequency domain imaging (OFDI) using swept laser sources is an emerging second-generation method for optical coherence tomography (OCT). Despite the widespread use of conventional OCT for retinal disease diagnostics, until now imaging the posterior eye segment with OFDI has not been possible. Here we report the development of a high-performance(More)
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