Wenwei Yu

Wenwei Yu
Chiba University · Graduate School of Engineering

Doctor of Philosophy

About

277
Publications
34,329
Reads
How we measure 'reads'
A 'read' is counted each time someone views a publication summary (such as the title, abstract, and list of authors), clicks on a figure, or views or downloads the full-text. Learn more
2,482
Citations

Publications

Publications (277)
Article
The electrical property (EP) of human tissues is a quantitative biomarker that facilitates early diagnosis of cancerous tissues. Magnetic resonance electrical properties tomography (MREPT) is an imaging modality that reconstructs EPs by the radio-frequency field in an MRI system. MREPT reconstructs EPs by solving analytic models numerically based o...
Article
Full-text available
Soft pneumatic actuators used in robotic rehabilitation gloves are classified into two types: whole-finger actuators with air chambers that cover the entire finger and modular actuators with chambers only above the finger joints. Most existing prototypes provide enough finger flexion support, but insufficient independent thumb abduction or oppositi...
Article
Full-text available
Applying soft actuators to hand motion assist for rehabilitation has been receiving increasing interest in recent years. Pioneering research efforts have shown the feasibility of soft rehabilitation gloves (SRGs). However, one important and practical issue, the effects of users’ individual differences in finger size and joint stiffness on both bend...
Article
During the past decade, soft robotics has become a growing new field, and researchers have developed different kinds of soft robots with different actuation technologies and mechanisms. Pneumatic artificial muscles (PAMs), as one kind of the most popular soft actuators, have been widely applied to robotic systems that assist persons. However, PAMs...
Conference Paper
Transcutaneous Electrical Nerve Stimulation (TENS) suppresses chronic pain by stimulating deep nerves near the fascia from electrodes on the skin's surface. TENS has different effects on patients of different ages due to the variation of the thickness of skin layers when one becomes older.In this paper, we aim to optimize the stimulation effectiven...
Preprint
The electrical property (EP) of human tissues is a quantitative biomarker that facilitates early diagnosis of cancerous tissues. Magnetic resonance electrical properties tomography (MREPT) is an imaging modality that reconstructs EPs by the radio-frequency field in an MRI system. MREPT reconstructs EPs by solving analytic models numerically based o...
Preprint
Full-text available
A permanent magnet array (PMA) is a preferred source of magnetic field for body-part-dedicated low-field (<0.5 T) portable magnetic resonance imaging (MRI) because it has a small footprint, no power consumption, and no need for a cooling system. The current popular PMA is limited by the transversal field below 100 mT, where advanced technologies de...
Article
Full-text available
Studies have developed various types of soft robotic gloves for hand rehabilitation in recent years. Most of the soft actuators achieved a sufficient thumb flexion assist while lacked opposition support which requires the coordination of thumb flexion and abduction-adduction. The difficulties for thumb support lie in the intrinsic complexity of thu...
Article
Full-text available
Purpose: Few investigations have been conducted on the selective stimulation of small-radius unmyelinated C nerves (C), which are critical to both the recovery of damaged nerves and pain suppression. The purpose of this study is to understand how an anodal pulse in an anodal-first stimulation could improve C-selectivity over myelinated nociceptive...
Article
Many countries face major challenges to ensure that their health and social care systems are ready for the growing numbers of older people (OP). As a way of realising ageing in place, assistive technologies such as home‐care robots are expected to play a greater role in the future. In Asia and Europe, robots are gradually being adopted as a public...
Article
Japan is facing a ‘care crisis’. There is an urgent need to ascertain the extent to which potential users are willing to use robotics-aided care before its roll-out as a formal policy. Based on our recent survey, we discuss home-care professionals’ real perceptions and their implications for the future development and implementation of home-care ro...
Article
A common problem for most strongly coupled magnetic resonance wireless power transfer systems is the dramatic efficiency drops by surrounding high-dielectric objects, e.g. people, caused by the narrow bandwidth of the systems due to a high quality factor (Q). In this paper, a compact broadband planar double-spiral resonator with a via is proposed t...
Article
Full-text available
Classification of pain levels from evoked electroencephalography (eEEG) has been achieved for the purpose of objective assessment of pain. However, differentiation of acute and chronic pain resulting from the activation of nociceptive nerves, the Aδ and C fibers, respectively, has remained unsolved, mainly due to the lack of effective features. Gra...
Preprint
Few investigations have been conducted on selective stimulation of small-radius unmyelinated C nerves (C), which is critical to both recoveries of damaged nerves and pain suppressions. The purpose of this study is to understand how an anodal pulse in an anodal-first stimulation could improve C-selectivity over myelinated nociceptive Aδ nerves (Aδ),...
Article
Validity of the band-type soft actuator device for feedback of prosthesis hand grasping was verified. This actuator can bend by compressed air and be wrapped around the respective parts of the prosthetic hand user’s body with a force proportional to prosthesis grasping force. Therefore, the actuator bands can provide the prosthesis grasping power i...
Article
Purpose This study aims to compare the level of needs for home-care robots amongst older adults, family caregivers and home-care staff and clarify the factors constituting these needs. Design/methodology/approach A cross-sectional, anonymous questionnaire survey was administered. It included 52 items related to needs for home-care robots rated on...
Preprint
Classification of pain-level-perception from evoked electroencephalography (eEEG) has been achieved for the purpose of objective assessment of pain. However, differentiating acute and chronic pain, resulting from the activation of nociceptive nerves, Aδ and C fibers, respectively, has remained unsolved, which is mainly due to the lack of effective...
Article
Aerosol jet printing (AJP) is a promising method for micro-scaled digital additive manufacturing for printed electronics. It usually requires a high sintering temperature (280 °C) and a long sintering time (e.g., 12 h on a glass substrate) to guarantee a high conductivity of the printed structures, which has limited AJP to only a few types of subst...
Conference Paper
We propose an encoding method which combines Transmit Array Spatial Encoding (TRASE) and spatial encoding magnetic field (SEM) to improve the image quality in a permanent-magnet-array (PMA)-based low-field portable MRI system with acceleration. TRASE is used to introduce phase shift to rearrange the signal points in local k-spaces, to gain more inf...
Article
Purpose To clarify potential users’ perceptions toward the development and social implementation of home-care robots in Japan, Ireland, and Finland. Methods Unsigned, self-administered questionnaires were distributed to adults aged 65 or older, family caregivers, and home-care/health and social care professionals. A total of 1,004 responses were c...
Conference Paper
Various robotic devices have been developed for home rehabilitation and support of therapists. Special attention has been focused on soft actuators due to their high viscoelasticity and flexibility, which can contribute to the safety and affinity with the users. However, most of them aimed at the assist of finger flexion, and few have been designed...
Article
Full-text available
It has been reported that stimulating nociceptive unmyelinated C nerves (C) near the sarcolemma could induce the secretion of endogenous opioids that relieve chronic pain. However, a substantial concern remains: concomitant stimulation might cause acute pain to nociceptive myelinated Aδ nerves (Aδ), which generally have a lower activation threshold...
Article
Full-text available
Because of the workforce shortage in Japan, the use of home-care robots, or carebots, is increasingly perceived as a realistic option. Developing and implementing these carebots requires careful consideration of the ethical implications for all types of users. Few studies, however, have addressed the ethical principles and concepts involved in care...
Article
Full-text available
Variability in individual pain sensitivity is a major problem in pain assessment. There have been studies reported using pain-event related potential (pain-ERP) for evaluating pain perception. However, none of them has achieved high accuracy in estimating multiple pain perception levels. A major reason lies in the lack of investigation of feature e...
Preprint
Full-text available
Point-of-care magnetic resonance imaging (MRI) requires clear images within a short scanning time, a small footprint of the scanner, and relatively low memory required for image reconstruction. A permanent magnet array (PMA)-based MRI system is a good candidate to supply a magnetic field due to its compactness and low power consumption. However, it...
Preprint
Full-text available
Aerosol jet printing (AJP) is a promising method for micro-scaled digital additive manufacturing for printed electronics. It usually requires a high sintering temperature (280 degree Celsius) and a long sintering time (e.g., 12 hours on a glass substrate) to guarantee a high conductivity of the printed structures, which has limited AJP to only a fe...
Preprint
Full-text available
Aerosol jet printing (AJP) is a promising method for microscale digital additive manufacturing for printed electronics. However, it requires a high sintering temperature (280 ° C) and a long sintering time (e.g. 12 hours on a glass substrate) to guarantee a highly conductive metallic structure, which confined AJP to limited types of substrates and...
Article
Validity of the watchband-type device for feedback of prosthesis hand grasping was investigated. The device is shaped like an index finger and thumb and the bands made by soft material using a three-dimensional printer can bend like a finger grasping motion by feeding air into inside of the band. Therefore, by wrapping around the wrist with a force...
Preprint
Full-text available
A common problem for most strongly coupled magnetic resonance (SCMR) wireless power transfer (WPT) systems is the dramatic efficiency drops by surrounding high-dielectric objects, e.g. people, caused by its limited bandwidth which is a result of a high quality factor (Q). In this paper, a compact broadband planar double-spiral resonator with a via...
Preprint
Sensory feedback is the fundamental driving force behind motor control and learning. However, the technology for low-cost and efficient sensory feedback remains a big challenge during stroke rehabilitation, and for prosthetic designs. Here we show that a low-cost accelerometer mounted on the finger can provide accurate decoding of many daily life m...
Article
Full-text available
Low-cost and portable magnetic resonance imaging (MRI) may make this imaging modality more accessible. Permanent-magnet-array is an option to supply a static magnetic field (B-field) with portability, low cost, and no power consumption. However, it has low field strength. Moreover, it does not have linear gradients, thus the signals and the images...
Conference Paper
Full-text available
A permanent magnet based low-field MRI system provides portability and affordability. However, the quality of the image is low due to a low signal-to-noise ratio (SNR). We propose a new deep learning structure which effectively integrates denoising-networks end-to-end to super-resolution-networks, to transfer the rich information available from one...
Preprint
Full-text available
Low-cost and portable magnetic resonance imaging (MRI) may make this imaging modality more accessible. Permanent-magnet-array is an option to supply the magnetic field (B-field) with portability, low cost, and no power consumption. However, it has low field strength. Moreover, it does not have linear gradients, thus the signals and the images are n...
Article
Full-text available
Microstrip line (MLIN)-based glucose sensors have been used for noninvasive glucose monitoring. However, the current MLIN-based solutions do not provide enough sensitivity. The reason for this is that they rely on the fringing field of an MLIN, which leads to a shallow penetration depth and thus low sensitivity. In this paper, we propose a sensitiv...
Chapter
Watchband-type soft pneumatic actuators were prototyped and tested by motion experiments. The actuators are soft device which is made from thermoplastic copolyester (TPC) by 3D printer. The actuator is for a device for feedback of prosthesis grasping force. The feedback device resembles a watch, and the parts corresponding to the watch wristband ar...
Article
Full-text available
Portable low-cost magnetic resonance imaging (MRI) systems have the potential to enable “point-of-care” and timely MRI diagnosis, and to make this imaging modality available to routine scans and to people in underdeveloped countries and areas. With simplicity, no maintenance, no power consumption, and low cost, permanent magnets/magnet arrays/magne...
Article
The watchband-type device shaped like an index finger and thumb was proposed. The bands can bend like a finger grasping motion by feeding air into inside of the band. Therefore, these finger-like bands are able to provide pressure on prosthesis user’s intact wrist by wrapping around the wrist with a force proportional to the hand prosthesis graspin...
Preprint
Full-text available
Portable low-cost MRI systems have the potential to enable point-of-care and timely MRI diagnosis, and to make this imaging modality available to routine scans and to underdeveloped areas. With simplicity, no maintenance, no power consumption, and low cost, permanent magnets or arrays are attractive to use as a source of magnetic field to realize p...
Article
This letter proposes a compact high-efficiency broadband microwave rectifier for energy harvesting. The proposed rectifier is designed to operate over a broad bandwidth spanning from 2 to 3 GHz and an input power dynamic range from 0 dBm to 10 dBm. In the proposed structure, a compact broadband low-loss matching network and a DC-pass filter with a...
Article
Conventional strongly coupled magnetic resonance (SCMR) wireless power transfer (WPT) systems have high quality factor ( $Q$ ), leading to limited system bandwidths. In practical applications, especially in human-involved environments, the resonant frequency of SCMR resonators will shift due to the effect of highly dielectric human body. In this l...
Preprint
Magnetic resonance electrical properties tomography is a challenging problem because of boundary inaccuracies and noise sensitivity. Several efforts have been reported on using machine learning methods for MRI image reconstruction, however, their work is computationally intensive. In this work, we show a ML-based reconstruction using PCA whitening f...
Article
Full-text available
In this letter, a microstrip line (MLIN)-based glucose sensor with significant improvement in sensitivity over sensors of the same category is proposed for noninvasive glucose monitoring. It has a T-shaped patterned signal line using the main field of an MLIN for sensing. Glucose under monitoring serves as the substrate of the MLIN. The pattern in...
Article
The main function of human hands is to grasp and manipulate objects, to which the thumb contributes the most. Various robotic hand rehabilitation devices have been developed for providing efficient hand function training. However, there have been few studies on thumb rehabilitation devices. Previously, we proposed a soft thumb rehabilitation device...
Article
Full-text available
Fiber-reinforced fluid-driven elastomer actuators have enabled the production of simple, low-cost and safe hand rehabilitation devices. However, so far, the actuators support only finger flexion-extension, and little has been reported on abduction-adduction, which is essential for manipulation tasks and grasping larger objects. The technical design...
Article
Full-text available
The lightness and softness of pneumatic artificial muscles (PAMs) contribute to their safe use in mechanical devices involved with humans. However, a PAM has limited range of motion (ROM) and a stroke-dependent output force. In this paper, a mechanism combined with a PAM and a speed-increasing gear was developed to improve the tradeoff relationship...
Article
Purpose: The aim of the present study was to describe the physiological effects of a combined training with breathing resistance and sustained physical exertion (CBS) program, which is a respiratory muscle training program designed to improve respiratory function and cardiorespiratory endurance, in young adults.Methods: Pre-and post-intervention me...
Article
Full-text available
Mobile robotics is a potential solution to home behavior monitoring for the elderly. For a mobile robot in the real world, there are several types of uncertainties for its perceptions, such as the ambiguity between a target object and the surrounding objects and occlusions by furniture. The problem could be more serious for a home behavior-monitori...
Article
Full-text available
Reconstruction of hand’s motion with Electroencephalography (EEG) signals is a challenging problem that has not been solved yet. Most related studies rely on a motion tracking system to record a sequence of hand coordinate values paired with biosignals, in order to train a mapping function between them. For amputees, this approach is not possible....
Article
Full-text available
During recent years, interest has been rising towards developing fluidic fiber-reinforced elastomer actuators for wearable soft robotics used in hand rehabilitation and power-assist. However, they do not enable finger abduction-adduction, which plays an important role in activities of daily living, when grasping larger objects. Furthermore, the dev...