scholarly journals High-speed spelling with a noninvasive brain–computer interface

2015 ◽  
Vol 112 (44) ◽  
pp. E6058-E6067 ◽  
Author(s):  
Xiaogang Chen ◽  
Yijun Wang ◽  
Masaki Nakanishi ◽  
Xiaorong Gao ◽  
Tzyy-Ping Jung ◽  
...  
Keyword(s):  
Information Transfer ◽  
High Speed ◽  
Target Identification ◽  
Modulation Method ◽  
Identification Algorithm ◽  
Calibration Data ◽  
Transfer Rates ◽  
Modulation And Demodulation ◽  
Individual Calibration ◽  
High Consistency

The past 20 years have witnessed unprecedented progress in brain–computer interfaces (BCIs). However, low communication rates remain key obstacles to BCI-based communication in humans. This study presents an electroencephalogram-based BCI speller that can achieve information transfer rates (ITRs) up to 5.32 bits per second, the highest ITRs reported in BCI spellers using either noninvasive or invasive methods. Based on extremely high consistency of frequency and phase observed between visual flickering signals and the elicited single-trial steady-state visual evoked potentials, this study developed a synchronous modulation and demodulation paradigm to implement the speller. Specifically, this study proposed a new joint frequency-phase modulation method to tag 40 characters with 0.5-s-long flickering signals and developed a user-specific target identification algorithm using individual calibration data. The speller achieved high ITRs in online spelling tasks. This study demonstrates that BCIs can provide a truly naturalistic high-speed communication channel using noninvasively recorded brain activities.

scholarly journals A Hybrid Speller Design Using Eye Tracking and SSVEP Brain–Computer Interface

Sensors ◽  
2020 ◽  
Vol 20 (3) ◽  
pp. 891 ◽  
Author(s):  
Malik M. Naeem Mannan ◽  
M. Ahmad Kamran ◽  
Shinil Kang ◽  
Hak Soo Choi ◽  
Myung Yung Jeong
Keyword(s):  
Eye Tracking ◽  
Classification Accuracy ◽  
Information Transfer ◽  
High Speed ◽  
Communication Channel ◽  
Computer Interface ◽  
Stimuli Responsive ◽  
Transfer Rates ◽  
Computer Interfaces ◽  
Large Numbers

Steady-state visual evoked potentials (SSVEPs) have been extensively utilized to develop brain–computer interfaces (BCIs) due to the advantages of robustness, large number of commands, high classification accuracies, and information transfer rates (ITRs). However, the use of several simultaneous flickering stimuli often causes high levels of user discomfort, tiredness, annoyingness, and fatigue. Here we propose to design a stimuli-responsive hybrid speller by using electroencephalography (EEG) and video-based eye-tracking to increase user comfortability levels when presented with large numbers of simultaneously flickering stimuli. Interestingly, a canonical correlation analysis (CCA)-based framework was useful to identify target frequency with a 1 s duration of flickering signal. Our proposed BCI-speller uses only six frequencies to classify forty-eight targets, thus achieve greatly increased ITR, whereas basic SSVEP BCI-spellers use an equal number of frequencies to the number of targets. Using this speller, we obtained an average classification accuracy of 90.35 ± 3.597% with an average ITR of 184.06 ± 12.761 bits per minute in a cued-spelling task and an ITR of 190.73 ± 17.849 bits per minute in a free-spelling task. Consequently, our proposed speller is superior to the other spellers in terms of targets classified, classification accuracy, and ITR, while producing less fatigue, annoyingness, tiredness and discomfort. Together, our proposed hybrid eye tracking and SSVEP BCI-based system will ultimately enable a truly high-speed communication channel.

scholarly journals A HIGH-SPEED BRAIN SPELLER USING STEADY-STATE VISUAL EVOKED POTENTIALS

2014 ◽  
Vol 24 (06) ◽  
pp. 1450019 ◽  
Author(s):  
MASAKI NAKANISHI ◽  
YIJUN WANG ◽  
YU-TE WANG ◽  
YASUE MITSUKURA ◽  
TZYY-PING JUNG
Keyword(s):  
Steady State ◽  
Information Transfer ◽  
High Speed ◽  
Target Identification ◽  
Real Life ◽  
Stimulus Presentation ◽  
Training Data ◽  
Information Transfer Rate ◽  
Electroencephalogram Eeg ◽  
Visual Evoked

Implementing a complex spelling program using a steady-state visual evoked potential (SSVEP)-based brain–computer interface (BCI) remains a challenge due to difficulties in stimulus presentation and target identification. This study aims to explore the feasibility of mixed frequency and phase coding in building a high-speed SSVEP speller with a computer monitor. A frequency and phase approximation approach was developed to eliminate the limitation of the number of targets caused by the monitor refresh rate, resulting in a speller comprising 32 flickers specified by eight frequencies (8–15 Hz with a 1 Hz interval) and four phases (0°, 90°, 180°, and 270°). A multi-channel approach incorporating Canonical Correlation Analysis (CCA) and SSVEP training data was proposed for target identification. In a simulated online experiment, at a spelling rate of 40 characters per minute, the system obtained an averaged information transfer rate (ITR) of 166.91 bits/min across 13 subjects with a maximum individual ITR of 192.26 bits/min, the highest ITR ever reported in electroencephalogram (EEG)-based BCIs. The results of this study demonstrate great potential of a high-speed SSVEP-based BCI in real-life applications.

scholarly journals Optimizing SSVEP-Based BCI System towards Practical High-Speed Spelling

Sensors ◽  
2020 ◽  
Vol 20 (15) ◽  
pp. 4186 ◽  
Author(s):  
Jiabei Tang ◽  
Minpeng Xu ◽  
Jin Han ◽  
Miao Liu ◽  
Tingfei Dai ◽  
...  
Keyword(s):  
Information Transfer ◽  
High Speed ◽  
Spatial Filter ◽  
Bayesian Posterior Probability ◽  
Temporal Filtering ◽  
Transfer Rates ◽  
Eeg Data ◽  
Electroencephalogram Eeg ◽  
The Brain ◽  
Peak Value

The brain–computer interface (BCI) spellers based on steady-state visual evoked potentials (SSVEPs) have recently been widely investigated for their high information transfer rates (ITRs). This paper aims to improve the practicability of the SSVEP-BCIs for high-speed spelling. The system acquired the electroencephalogram (EEG) data from a self-developed dedicated EEG device and the stimulation was arranged as a keyboard. The task-related component analysis (TRCA) spatial filter was modified (mTRCA) for target classification and showed significantly higher performance compared with the original TRCA in the offline analysis. In the online system, the dynamic stopping (DS) strategy based on Bayesian posterior probability was utilized to realize alterable stimulating time. In addition, the temporal filtering process and the programs were optimized to facilitate the online DS operation. Notably, the online ITR reached 330.4 ± 45.4 bits/min on average, which is significantly higher than that of fixed stopping (FS) strategy, and the peak value of 420.2 bits/min is the highest online spelling ITR with a SSVEP-BCI up to now. The proposed system with portable EEG acquisition, friendly interaction, and alterable time of command output provides more flexibility for SSVEP-based BCIs and is promising for practical high-speed spelling.

scholarly journals Modelling the brain response to arbitrary visual stimulation patterns for a flexible high-speed BCI

2018 ◽  
Author(s):  
Sebastian Nagel ◽  
Martin Spüler
Keyword(s):  
Information Transfer ◽  
High Speed ◽  
Visual Stimulation ◽  
Traditional Approach ◽  
Brain Response ◽  
Trial Duration ◽  
General Process ◽  
Transfer Rates ◽  
The Brain ◽  
Unlimited Amount

AbstractVisual evoked potentials (VEPs) can be measured in the EEG as response to a visual stimulus. Commonly, VEPs are displayed by averaging multiple responses to a certain stimulus or a classifier is trained to identify the response to a certain stimulus. While the traditional approach is limited to a set of predefined stimulation patterns, we present a method that models the general process of VEP generation and thereby can be used to predict arbitrary visual stimulation patterns from EEG and predict how the brain responds to arbitrary stimulation patterns. We demonstrate how this method can be used to model single-flash VEPs, steady state VEPs (SSVEPs) or VEPs to complex stimulation patterns. It is further shown that this method can also be used in a BCI to allow information transfer rates of more than 470 bit/min and lead to more flexible BCIs with a virtually unlimited amount of targets and any desired trial duration.

Design and Implementation of Digital Communication Platform Based on FPGA/DSP

2014 ◽  
Vol 981 ◽  
pp. 398-401
Author(s):  
Sheng Guo Zhou ◽  
Wen Jing Shang ◽  
Nan Wang ◽  
Victor Rublev
Keyword(s):  
Digital Communication ◽  
Software Radio ◽  
Modulation Method ◽  
Signal Process ◽  
Communication Platform ◽  
Modulation And Demodulation ◽  
Design And Implementation ◽  
Hardware System ◽  
Radio Method

A method to design and implement digital communication platform was in introduced in this paper. The platform based on software radio method can change modulation method conveniently without the change of hardware system because it used FPGA and DSP to do modulation and signal process. The QPSK modulation and demodulation was implemented in the platform to test this platform.

Using Dual Cam Tracks for High Speed Rigid Body Motion

1998 ◽  
Author(s):  
Clay Cooper ◽  
Stephen Derby
Keyword(s):  
Rigid Body ◽  
High Speed ◽  
Rigid Body Motion ◽  
Body Motion ◽  
Transfer Rates ◽  
Track System ◽  
Selection Of

Abstract Rigid Body Motion has long been one of the standard problems for kinematicians. For high speed transfer rates, an industrial example of using a dual cam track system to achieve better performance is documented. The dual track establishes both a positional and orientational location of the followers. The selection of this mechanism type is discussed.

High Speed Packet Access Broadband Mobile Communications

2009 ◽  
pp. 595-604
Author(s):  
Athanassios C. Iossifides ◽  
Spiros Louvros
Keyword(s):  
Mobile Communications ◽  
Rural Areas ◽  
High Speed ◽  
Data Transfer ◽  
Mobile Wimax ◽  
Major Step ◽  
Transfer Rates ◽  
Mobile Broadband ◽  
History Of ◽  
Broadband Market

Mobile broadband communications systems have already become a fact during the last few years. The evolution of 3G Universal Mobile Telecommunications Systems (UMTS) towards HSDPA/HSUPA systems have already posed a forceful solution for mobile broadband and multimedia services in the market, making a major step ahead of the main competitive technology, that is, WiMax systems based on IEEE 802.16 standard. According to the latest analyses (GSM Association, 2007; Little, 2007), while WiMax has gained considerable attention the last few years, HSPA is expected to dominate the mobile broadband market. The main reasons behind this forecast are: • HSPA is already active in a significant number of operators and is going to be established for the majority of mobile broadband networks worldwide over the next five years, while commercial WiMax systems are only making their first steps. • Mobile WiMax is a competitive technology for selection by operators in only a limited number of circumstances where conditions are favourable. Future mobile WiMax systems may potentially achieve higher data transfer rates than HSPA, though cell coverage for these rates is expected to be substantially smaller. In addition, WiMax technology is less capable in terms of voice traffic capacity, thus limiting market size and corresponding revenues. • In order to overcome the aforementioned disadvantages, WiMax commercial launches are expected to introduce a relative CAPEX disadvantage of at least 20–50% comparing to HSPA, in favorable cases, while there are indications of an increase by up to 5–10 times when accounting for rural areas deployments. The short commercial history of HSDPA (based on Rel.5 specifications of 3GPP) started in December of 2005 (first wide scale launch by Cingular Wireless, closely followed by Manx Telecom and Telekom Austria). Bite Lietuva (Lithuania) was the first operator that launched 3.6 Mbps. HSUPA was first demonstrated by Mobilkom Austria in November 2006 and soon launched commercially in Italia by 3 in December 2006. Mobilkom Austria launched the combination of HSDPA at 7.2 Mbps and HSUPA in February 2007. By September of 2007, less than two years after the first commercial launch, 141 operators in 65 countries (24 out of 27 in EU) have already gone commercial with HSDPA with 38 operators among them supporting a 3.6 Mbps downlink. In addition, devices supporting HSDPA/HSUPA services are rapidly enriched. 311 devices from 79 suppliers have already been available by September 2007, including handsets, data cards, USB modems, notebooks, wireless routers, and embedded modules (http://hspa.gsmworld.com).

Sign in / Sign up

Export Citation Format

Share Document