筋電義手処方支援を目的としたバーチャルトレーニングシステムの開発

内容の要約広島大学(Hiroshima University)博士(工学)Doctor of Engineeringdoctora

A Voice Signal-Based Manipulation Method for the Bio-Remote Environment Control System Based on Candidate Word Discriminations

This paper proposes a voice signal-based manipulation method for the Bio-Remote environment control system. The proposed system learns relationships between multiple candidate words’ phonemes extracted by a largevocabulary speaker-independent model and control commands based on a self-learning look-up table. This allows the user to control various devices even if false recognition words are extracted. Experimental results showed that the method accurately discriminate slurred words (average discrimination rate: 93.9±2.40 [%]), and that participants were able to voluntarily control domestic appliances.This work was supported by JSPS KAKENHI Grant Number JP26330226

A Training Method for the Speech Controlled Environmental Control System Based on Candidate Word Discriminations

This paper proposes a concept of a training system for the speech controlled environmental control system: Bio-Remote based on candidate word discriminations. The proposed system can provide three-types of voice signal training: (1) volume, (2) tempo/timing and (3) candidate word which are important for accurate speech recognition based on false recognition results. During the training, such three kinds of features are extracted from measured voice signals and visually and auditory fed back to the user in real time. This allows the user to train speech abilities even if false recognition results are extracted because of slurred speech. The efficacy of the proposed system was demonstrated through training experiments for slurred speech conducted with healthy participants. The results showed that the proposed system was capable for the training of speech abilities.This work was partially supported by JSPS/MEXT KAKENHI Grant Numbers 17K12723 and 26330226

Amphiregulin and Epiregulin mRNA expression in primary colorectal cancer and corresponding liver metastases

<p>Abstract</p> <p>Background</p> <p>Amphiregulin (AREG) and Epiregulin (EREG), ligands of EGFR, are reported to be predictive biomarkers of colorectal cancer patients treated with Cetuximab, an anti-EGFR antibody. The purpose of this study is to determine the correlation of AREG and EREG expression between primary colorectal cancer and corresponding liver metastases.</p> <p>Methods</p> <p>One hundred twenty colorectal cancer patients with liver metastases (100 with synchronous metastases, 20 with metachronous) were evaluated. No patients had ever received anti-EGFR antibody agents. AREG and EREG mRNA expression from both the primary tumor and liver metastases were measured using real-time RT-PCR. KRAS codon 12, 13 mutation status was analyzed by direct sequencing.</p> <p>Results</p> <p>Modest, but significant, correlations were observed between primary tumor and corresponding liver metastases in both AREG mRNA expression (Rs = 0.54, p < 0.0001) and EREG mRNA expression (Rs = 0.58, p < 0.0001). AREG and EREG mRNA expression was strongly correlated in both the primary tumor (Rs = 0.81, p < 0.0001) and the liver metastases (Rs = 0.87, p < 0.0001). No significant survival difference was observed between low and high AREG or EREG patients when all 120 patients were analyzed. However, when divided by KRAS status, KRAS wild-type patients with low EREG mRNA levels in the primary site showed significantly better overall survival rates than those with high levels (p = 0.018). In multivariate analysis, low EREG expression was significantly associated with better overall survival (p = 0.006).</p> <p>Conclusions</p> <p>AREG and EREG expression showed a modest correlation between primary tumor and liver metastases. As EREG mRNA expression was associated with decreased survival, it is appeared to be a useful prognostic marker in KRAS wild-type patients who never received anti-EGFR therapy.</p

A Human Reaching Movement Model for Myoelectric Prosthesis Control

This paper proposes a reaching movement model for the generation of desired trajectories within a myoelectric prosthesis training system. First, an experiment was performed to observe reaching movements with a non-impaired subject and a myoelectric prosthesis user. Reaching movements made by the prosthesis user were then adopted to construct a model based on a logistic function. The proposed model can be used to generate three trajectory types with a bell-shaped speed profile with the adjustment of only a few parameters.This work was partially supported by a Grant-in-Aid for Young Scientists B Number 26730111

Enhancing the Hot-Phonon Bottleneck Effect in a Metal Halide Perovskite by Terahertz Phonon Excitation

ハライドペロブスカイト半導体においてテラヘルツ励起によるホットキャリアの長寿命化を実現 --太陽電池材料のフォノン操作による高効率化への新たな指針--. 京都大学プレスリリース. 2021-02-19.We investigate the impact of phonon excitations on the photoexcited carrier dynamics in a lead-halide perovskite CH3NH3PbI3, which hosts unique low-energy phonons that can be directly excited by terahertz pulses. Our time-resolved photoluminescence measurements reveal that strong terahertz excitation prolongs the cooling time of hot carriers, providing direct evidence for the hot-phonon bottleneck effect. In contrast to the previous studies where phonons are treated as a passive heat bath, our results demonstrate that phonon excitation can significantly perturb the carrier relaxation dynamics in halide perovskites through the coupling between transverse- and longitudinal-optical phonons

A virtual myoelectric prosthesis training system capable of providing instructions on hand operations

This article proposes a virtual hand and a virtual training system for controlling the MyoBock—the most commonly used myoelectric prosthetic hand worldwide. As the virtual hand is controlled using the method also adopted for the MyoBock hand, the proposed system provides upper-limb amputees with operation sensibilities similar to those experienced in MyoBock control. It can also display an additional virtual hand for the provision of instructions on hand operation, such as the recommended posture for object grasping and the trajectory desirable to reach a target. In virtual hand control experiments conducted with an amputee to evaluate the proposed virtual hand’s operability, the subject successfully performed stable opening and closing with high discrimination rates (89.3±6.65%), thanks to the virtual hand’s incorporation of the MyoBock’s operational characteristics. A training experiment using the proposed system was also conducted with eight healthy participants over a period of 5 days. The participants were asked to perform the box and block test using the MyoBock hand in a real environment on the first and final days. The results showed that the number of blocks transported in 1 min significantly increased and that the participants using the instruction virtual hand changed the orientation of the hand approaching blocks from vertical to lateral. The outcomes of the experiment indicate that the proposed system can be used to improve MyoBock hand control operation both quantitatively and qualitatively.This work was partially supported by a Grant-in-Aid for Young Scientists B Number 26730111 and a Grant-in-Aid for Scientific Research C Number 26462242

Orthogonal antibody testing for COVID-19 among healthcare workers in a non-epidemic place and time: Japan's Iwate Prefecture, May 18-31, 2020

Of the 47 prefectures in Japan, Iwate had the fewest cases of coronavirus disease 2019 (COVID-19), with the first diagnosis officially confirmed on July 28, 2020. A baseline serological survey of COVID-19 antibodies is essential to accurately evaluate an epidemic outbreak. The primary purpose of this study was to determine pre-epidemic prevalence of COVID-19 antibodies among healthcare workers, using two laboratory-based quantitative tests. In addition, a point-of-care (POC) qualitative test, rapid, simple, and convenient for primary care clinics, was compared with the laboratory-based tests. All antibody tests were performed on serum from 1,000 healthcare workers (mean age, 40 ± 11 years) in Iwate Prefectural Central Hospital, May 29-31, 2020. A COVID-19 case was defined as showing positive results in both laboratory-based quantitative tests. None of 1,000 samples had positive results in both of the laboratory immunoassays. The POC test showed positive results in 33 of 1,000 samples (3.3%) (95% confidence interval:2.19-4.41), but no samples were simultaneously positive in both laboratory-based tests. In conclusion, COVID-19 cases were not serologically confirmed by a baseline control study of healthcare workers at our hospital in late May, 2020. Moreover, the POC qualitative test may offer no advantage in areas with very low prevalence of COVID-19, due to higher false-positive reactions compared with laboratory-based quantitative immunoassays