An SSVEP-Based BCI with Adaptive Time-Window Length

AbstractPhotoacoustic imaging has the advantages of high contrast and deep imaging depth. However, with the increasing of imaging depth, the signal-to-noise ratio (SNR) of the detected signal decreases, due to the light scattering that seriously affects the recovery image quality. In this paper, we experimentally demonstrated that higher contrast photoacoustic imaging was achieved using photoacoustic wavefront shaping technology in the presence of light scattering and low SNR signals. The imaging contrast is improved from 1.51 to 5.30. More importantly, we propose a dynamic time window method for the photoacoustic signal extraction algorithm, named correlation detection of adaptive time window, which further improves the contrast of photoacoustic imaging to 9.57. Our method effectively improves the contrast of photoacoustic imaging through scattering media.

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1P444 The correlation between the environmental adaptability and the diversity of the time window length of spatio-temporal response selectivity(18. Neuro-infomatics,Poster Session,Abstract,Meeting Program of EABS &BSJ 2006)

Seibutsu Butsuri ◽

10.2142/biophys.46.s257_4 ◽

2006 ◽

Vol 46 (supplement2) ◽

pp. S257

Author(s):

Hiroyuki Ohta ◽

Yukio Gunji

Keyword(s):

Poster Session ◽

Time Window ◽

Window Length ◽

Temporal Response ◽

Meeting Program ◽

Environmental Adaptability ◽

Spatio Temporal

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A study of acoustic characteristics of voluntary expiratory sounds produced before and immediately after swallowing

Scientific Reports ◽

10.1038/s41598-021-04624-7 ◽

2022 ◽

Vol 12 (1) ◽

Author(s):

Shoma Hattori ◽

Shinji Nozue ◽

Yoshiaki Ihara ◽

Koji Takahashi

Keyword(s):

Fourier Transform ◽

Fast Fourier Transform ◽

Time Window ◽

Maximum Amplitude ◽

Comparison Method ◽

Window Length ◽

Acoustic Characteristics ◽

The Mean ◽

Time Waveform ◽

The Relationship

AbstractTo evaluate the expiratory sounds produced during swallowing recorded simultaneously with videofluorographic examination of swallowing (VF) using fast Fourier transform (FFT), and to examine the relationship between dysphagia and its acoustic characteristics. A total of 348 samples of expiratory sounds were collected from 61 patients with dysphagia whose expiratory sounds were recorded during VF. The VF results were evaluated by one dentist and categorized into three groups: safe group (SG), penetration group (PG), and aspiration group (AG). The duration and maximum amplitude of expiratory sounds produced were measured as the domain characteristics on the time waveform of these sounds and compared among the groups. Time window-length appropriate for FFT and acoustic discriminate values (AD values) of SG, PG, and AG were also investigated. The groups were analyzed using analysis of variance and Scheffé's multiple comparison method. The maximum amplitude of SG was significantly smaller than those of PG and AG. The mean duration in SG (2.05 s) was significantly longer than those in PG (0.84 s) and AG (0.96 s). The AD value in SG was significantly lower than those in PG and AG. AD value detects penetration or aspiration, and can be useful in screening for dysphagia.

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