Hideo Tsurushima

We have been developing a cognitive, brain-machine interface (BMI)-based, training system called the “Neurotrainer.” This system was initially designed to detect averaged event-related potentials (ERPs), which reflect momentary heightened attention, allowing these individuals to participate in cognitive training without the need for hands-on interaction. In this study, we expanded our method to decode single-trial ERPs during a racing game, with the expectation that neurofeedback would accelerate the training process. We assessed the performance of the prototype system with healthy volunteers. The decoding accuracy of the target character was approximately 54% for a single trial and 83% for five trials (chance level = 12.5%). Moreover, ERP responses were stronger in the feedback condition than in the no-feedback condition. These results suggest that the BMI could be an effective tool for cognitive training, as real-time neurofeedback influences the brain activation of the players.

Edema is a common symptom of kidney disease, and quantitative measurement of edema is desired. This paper presents a method to estimate the degree of edema from facial images taken before and after dialysis of renal failure patients. As tasks to estimate the degree of edema, we perform pre- and post-dialysis classification and body weight prediction. We develop a multi-patient pre-training framework for acquiring knowledge of edema and transfer the pre-trained model to a model for each patient. For effective pre-training, we propose a novel contrastive representation learning, called weight-aware supervised momentum contrast (WeightSupMoCo). WeightSupMoCo aims to make feature representations of facial images closer in similarity of patient weight when the pre- and post-dialysis labels are the same. Experimental results show that our pre-training approach improves the accuracy of pre- and post-dialysis classification by 15.1% and reduces the mean absolute error of weight prediction by 0.243 kg compared with training from scratch. The proposed method accurately estimate the degree of edema from facial images; our edema estimation system could thus be beneficial to dialysis patients.

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BACKGROUND Sharing progress notes as a common social capital is essential in research and education, but the content of progress notes is sensitive and needs to be kept confidential. Publishing actual progress notes are difficult due to privacy concerns. OBJECTIVE This study aims to generate a large repository of pseudo-progress notes of authentic quality. We focused on two requirements for authentic quality: the validity and consistency of the data, from the perspective of medical practice, and the empirical and semantic characteristics of progress notes, such as shorthand styles used for reporting changes in a patient's physical status, long narrative sentences detailing patient anxiety, and interprofessional communications. METHODS We proposed a practical framework that consists of a simulation of the notes and evaluation of the simulated notes. The framework utilized two human cognitive traits: (1) the ability to use imitation to simulate objects with diverse characteristics without background knowledge and (2) the use of comparison as a strategy for deep thinking. This enabled crowd workers to generate a large number of progress notes. Our framework involved three steps. In step 1, crowd workers imitated actual progress notes decomposed into subject data (S), object data (O), and assessment and plan (A/P). These imitated texts were then shuffled and recomposed in S, O, and A/P in order to create simulated progress notes. In step 2, crowd workers identified the characteristics of actual progress notes based on comparisons between actual and dummy progress notes. These characteristics were clustered based on their similarities. Each cluster exhibited the empirical and semantic characteristics of the actual progress notes. Finally, in step 3, the texts from step 1 that exhibited the identified characteristics from step 2 were evaluated as quality-guaranteed progress notes that met the two requirements. All data were preprocessed to protect patient privacy. RESULTS Step 1: By recomposing the 700 imitated texts, 9,856 simulated progress notes were generated. Step 2: 3,938 differences between actual progress notes and dummy progress notes were identified. After clustering, 166 characteristics were evaluated to be appropriate as empirical and semantic characteristics of the actual progress notes. Step 3: 500 crowd workers demonstrated that 83.0% of the simulated progress notes satisfied at least one of the characteristics obtained in step 2. The crowd workers' artificially-reproduced progress notes were evaluated to determine the most realistic, based on four metrics: disease, morpheme, readability, and reality. CONCLUSIONS Our results demonstrated that crowd workers could generate and evaluate highly professional documents. We have made our large repository of high-quality crowdsourced progress notes publicly available, and we encourage their use in the development of medical education and research.

Background: Gait disturbance often occurs in stroke survivors. Recovery of walking function is challenging, as some gait disturbance due to hemiparesis often remains even after rehabilitation therapy, presenting a major obstacle towards regaining activities-of-daily-living performance and achieving social reintegration. Objective: This study aims to clarify the effectiveness of a walking program involving the wearable Hybrid Assistive Limb (HAL-TS01) robotic exoskeleton for improving walking ability in stroke patients with hemiparesis and stagnant recovery despite ongoing rehabilitation. Methods: This is a multicenter, randomized, parallel-group, controlled study (HAL group, n=27; control group, n=27). The study period includes preintervention observation (until stagnant recovery), intervention (HAL-based walking therapy or conventional rehabilitation; 5 weeks), and postintervention observation (2 weeks). Following provision of informed consent and primary registration, the patients undergo conventional rehabilitation for preintervention observation, during which the recovery of walking ability is monitored to identify patients with stagnant recovery (based on weekly assessments using the 10-meter maximum walking speed [MWS] test). Patients with an MWS of 30-60 m/minute and insufficient weekly improvement in MWS undergo secondary registration and are randomly assigned to undergo HAL-based walking therapy (HAL group) or conventional rehabilitation (control group). The primary outcome is the change in MWS from baseline to the end of the 5-week intervention. Results: This study began in November 2016 and is being conducted at 15 participating facilities in Japan. Conclusions: Assessments of walking ability vary greatly and it is difficult to define the threshold for significant differences. To reduce such variability, our study involves conducting conventional rehabilitation to the point of saturation before starting the intervention. Stagnation in the recovery of walking ability despite conventional rehabilitation highlights the limits of current medical care. The present study may bring evidence that HAL-based therapy can overcome such limitations and induce added recovery of walking ability, which would promote the use of HAL technology in the clinical setting. Trial Registration: UMIN Clinical Trials Registry UMIN000024805; https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000028545

BACKGROUND Gait disturbance often occurs in stroke survivors. Recovery of walking function is challenging, as some gait disturbance due to hemiparesis often remains even after rehabilitation therapy, presenting a major obstacle towards regaining activities-of-daily-living performance and achieving social reintegration. OBJECTIVE This study aims to clarify the effectiveness of a walking program involving the wearable Hybrid Assistive Limb (HAL-TS01) robotic exoskeleton for improving walking ability in stroke patients with hemiparesis and stagnant recovery despite ongoing rehabilitation. METHODS This is a multicenter, randomized, parallel-group, controlled study (HAL group, n=27; control group, n=27). The study period includes preintervention observation (until stagnant recovery), intervention (HAL-based walking therapy or conventional rehabilitation; 5 weeks), and postintervention observation (2 weeks). Following provision of informed consent and primary registration, the patients undergo conventional rehabilitation for preintervention observation, during which the recovery of walking ability is monitored to identify patients with stagnant recovery (based on weekly assessments using the 10-meter maximum walking speed [MWS] test). Patients with an MWS of 30-60 m/minute and insufficient weekly improvement in MWS undergo secondary registration and are randomly assigned to undergo HAL-based walking therapy (HAL group) or conventional rehabilitation (control group). The primary outcome is the change in MWS from baseline to the end of the 5-week intervention. RESULTS This study began in November 2016 and is being conducted at 15 participating facilities in Japan. CONCLUSIONS Assessments of walking ability vary greatly and it is difficult to define the threshold for significant differences. To reduce such variability, our study involves conducting conventional rehabilitation to the point of saturation before starting the intervention. Stagnation in the recovery of walking ability despite conventional rehabilitation highlights the limits of current medical care. The present study may bring evidence that HAL-based therapy can overcome such limitations and induce added recovery of walking ability, which would promote the use of HAL technology in the clinical setting. CLINICALTRIAL UMIN Clinical Trials Registry UMIN000024805; https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000028545

Purpose: Reperfusion injury after thrombolytic therapy or mechanical thrombectomy would adverse neurological outcome. Generation of reactive oxygen species (ROS) due to reperfusion is relevant for aggravation. The development of drug therapy for scavenging free radical is expected to lead to better neurological prognosis. We developed a new core-shell type nanoparticle, RNP (radical containing nanoparticle), which consists of micelle containing 4-amino-TEMPO. The purpose of this study is to evaluate an efficacy of intra-arterial injection of RNP after reperfusion using tMCAO mice model. Methods: C57BL/6J mice underwent tMCAO for 60 minutes and received RNP by intra-arterial injection from common carotid artery. We evaluated infarction size, neurological scale, and Evans blue extravasation at 24h after reperfusion. RNP distribution was detected by rhodamine labeling. We further examined immunofluorescense of CD31, Occludin, TUNEL, dihydroethydium, and 8-hydroxy-deoxyguanosine (8-OHdG). Multiple free radical scavenging capacity of ischemic hemisphere was analyzed by Electron Paramagnetic Resonance (EPR). Results: RNPs were detected in endothelial cells and around neuronal cells in the ischemic lesion. The infarction size, neurological scale, Evans blue extravasation of the mice treated by RNP were significantly lower than the mice treated by PBS , control group. Intra-arterial RNP treatment preserved endothelium and expression of occludin in the ischemic brain. Further, apoptosis of neuronal cells and production of superoxide anions and 8OHdG were suppressed. By using EPR, multiple ROS scavenging capacity (•OH, •ROO, •O ₂ ^- ) of the ischemic brain treated by RNP were higher. Conclusions: These results suggest that intra-arterial injection of RNP have efficacy of neurovascular unit protection and reduce infarction volume by improving multiple ROS scavenging capacity.

Surface-mediated gene transfer systems using biocompatible calcium phosphate (CaP)-based composite layers have attracted attention as a tool for controlling cell behaviors. In the present study we aimed to demonstrate the potential of CaP-based composite layers to mediate area-specific dual gene transfer and to stimulate cells on an area-by-area basis in the same well. For this purpose we prepared two pairs of DNA–fibronectin–apatite composite (DF-Ap) layers using a pair of reporter genes and pair of differentiation factor genes. The results of the area-specific dual gene transfer successfully demonstrated that the cells cultured on a pair of DF-Ap layers that were adjacently placed in the same well showed specific gene expression patterns depending on the gene that was immobilized in theunderlying layer. Moreover, preliminary real-time PCR results indicated that multipotential C3H10T1/2 cells may have a potential to change into different types of cells depending on the differentiation factor gene that was immobilized in the underlying layer, even in the same well. Because DF-Ap layers have a potential to mediate area-specific cell stimulation on their surfaces, they could be useful in tissue engineering applications.