24 research outputs found
Noncontact brain-computer interface based on steady-state pupil light reflex using independent bilateral eyes stimulation
Steady-state visual evoked potential (SSVEP), which uses blinking light stimulation to estimate the attending target, has been known as a communication technique with severe motor disabilities such as ALS and Locked-in-syndrome. Recently, it was reported that pupil diameter vibration based on pupillary light reflex has been observed in the attending target with a constant blinking frequency. This fact suggests the possibility of a noncontact BCI using pupillometers as alternatives to contacting scalp electrodes. In this study, we show an increment in the number of communication channels by stimulating both eyes alone or in combination with different frequencies. The number of selective targets becomes twice the number of frequencies using this method. Experiments are conducted by recruiting three healthy participants. We prepare six target patterns comprising three frequencies and detect the target using a coefficient of correlation of power spectrum between the pupil diameter and stimulus signal. Consequently, the average classification accuracy of the three participants of approximately 83.4% is achieved. The findings of this study demonstrate the feasibility of noncontact BCI systems
Design of the Forced Vibration System for Detecting the Robotic Forceps Contact with the Organ
Brain-controlled cycling system for rehabilitation following paraplegia with delay-time prediction
Objective: Robotic rehabilitation systems have been investigated to assist with motor dysfunction recovery in patients with lower-extremity paralysis caused by central nervous system lesions. These systems are intended to provide appropriate sensory feedback associated with locomotion. Appropriate feedback is thought to cause synchronous neuron firing, resulting in the recovery of function. Approach: In this study, we designed and evaluated an ergometric cycling wheelchair, with a brain-machine interface (BMI), that can force the legs to move by including normal stepping speeds and quick responses. Experiments were conducted in five healthy subjects and one patient with spinal cord injury (SCI), who experienced the complete paralysis of the lower limbs. Event-related desynchronization (ERD) in the β band (18‐28 Hz) was used to detect lower-limb motor images. Main results: An ergometer-based BMI system was able to safely and easily force patients to perform leg movements, at a rate of approximately 1.6 seconds/step (19 rpm), with an online accuracy rate of 73.1% for the SCI participant. Mean detection time from the cue to pedaling onset was 0.83±0.31 s Significance: This system can easily and safely maintain a normal walking speed during the experiment and be designed to accommodate the expected delay between the intentional onset and physical movement, to achieve rehabilitation effects for each participant. Similar BMI systems, implemented with rehabilitation systems, may be applicable to a wide range of patients
Amino acid polymorphisms in human histocompatibility leukocyte antigen class II and proinsulin epitope have impacts on type 1 diabetes mellitus induced by immune-checkpoint inhibitors
IntroductionImmune-checkpoint inhibitors are effective in various advanced cancers. Type 1 diabetes mellitus induced by them (ICI-T1DM) is a serious complication requiring prompt insulin treatment, but the immunological mechanism behind it is unclear.MethodsWe examined amino acid polymorphisms in human histocompatibility leukocyte antigen (HLA) molecules and investigated proinsulin epitope binding affinities to HLA molecules.Results and DiscussionTwelve patients with ICI-T1DM and 35 patients in a control group without ICI-T1DM were enrolled in the study. Allele and haplotype frequencies of HLA-DRB1*04:05, DQB1*04:01, and most importantly DPB1*05:01 were significantly increased in patients with ICI-T1DM. In addition, novel amino acid polymorphisms in HLA-DR (4 polymorphisms), in DQ (12 polymorphisms), and in DP molecules (9 polymorphisms) were identified. These amino acid polymorphisms might be associated with the development of ICI-T1DM. Moreover, novel human proinsulin epitope clusters in insulin A and B chains were discovered in silico and in vitro peptide binding assays to HLA-DP5. In conclusion, significant amino acid polymorphisms in HLA-class II molecules, and conformational alterations in the peptide-binding groove of the HLA-DP molecules were considered likely to influence the immunogenicity of proinsulin epitopes in ICI-T1DM. These amino acid polymorphisms and HLA-DP5 may be predictive genetic factors for ICI-T1DM
Weak Electric Current Treatment to Artificially Enhance Vascular Permeability in Embryonated Chicken Eggs
Technologies that overcome the barrier presented by vascular endothelial cells are needed to facilitate targeted delivery of drugs into tissue parenchyma by intravenous administration. We previously reported that weak electric current treatment (ET: 0.3–0.5 mA/cm2) applied onto skin tissue in a transdermal drug delivery technique termed iontophoresis induces cleavage of intercellular junctions that results in permeation of macromolecules such as small interfering RNA and cytosine-phosphate-guanine (CpG) oligonucleotide through the intercellular space. Based on these findings, we hypothesized that application of ET to blood vessels could promote cleavage of intercellular junctions that artificially induces increase in vascular permeability to enhance extravasation of drugs from the vessels into target tissue parenchyma. Here we investigated the effect of ET (0.34 mA/cm2) on vascular permeability using embryonated chicken eggs, which have blood vessels in the chorioallantoic membrane (CAM), as an animal model. ET onto the CAM of the eggs significantly increased extravasation of intravenously injected calcein (M.W. 622.6), a low molecular weight compound model, and the macromolecule fluorescein isothiocyanate (FITC)-dextran (M.W. 10000). ET-mediated promotion of penetration of FITC-dextran through vascular endothelial cells was also observed in transwell permeability assay using monolayer of human umbilical vein endothelial cells without induction of obvious cellular damage. Confocal microscopy detected remarkable fluorescence derived from injected FITC-dextran in blood vessel walls. These results in embryonated chicken eggs suggest that ET onto blood vessels could artificially enhance vascular permeability to facilitate extravasation of macromolecules from blood vessels
DLC Inner Wall Hybrid Coating of Narrow Tubes by the 2nd Harmonic ECR Micro Plasma
ナノダイナミクス国際シンポジウム 平成22年1月21日(木) 於長崎大学Nagasaki Symposium on Nano-Dynamics 2010 (NSND2010), January 21, 2010, Nagasaki University, Nagasaki, Japan, Invited Lectur
Relative Position Estimation for Formation Control with the Fusion of Predicted Future Information and Measurement Data
This paper addresses a relative position estimation problem for formation control of multiple robots. In the authors' previous paper, a relative position estimation method has been proposed, which fuses information from distance sensors and wireless communication. In this method, it is assumed that the robots communicate with others by wireless devices at every control sampling time. Therefore, depending on the performance of the wireless devices, the control sampling time should be set to a large value, which can degrade control performance. In this paper, we propose a new relative position estimation method, which is effective even if the communication sampling time is longer than the control sampling time. The idea in this method is to use predicted information on the time-series of the control input from detected robots. We develop a method to generate the time-series of the predicted control input for successful estimation. Finally, we verify the effectiveness of the proposed method by simulations and an experiment