Seungjong Kim

There is no distinct clinical classification of post-stroke hemiplegic gaits. However, in contrast to previous studies, more optimal gait types with a high classification performance fully utilizing the kinematic features were identified in this study.

In this paper, an online diagnosis scheme for sensor faults in an active magnetic bearing system equipped with built-in force transducers is proposed. The scheme, utilizing redundant signals, i.e., displacement, current and force, is based on the causality between faults and symptoms. The main advantage of the scheme is that it is simple and efficient, because monitoring the symptom only is enough to diagnose a sensor fault with no elaborate signal processing. Experiments were also performed to

The accurate detection of the gait phase is crucial for monitoring and diagnosing neurological and musculoskeletal disorders and for the precise control of lower limb assistive devices. In studying locomotion mode identification and rehabilitation of neurological disorders, the concept of modular organization, which involves the co-activation of muscle groups to generate various motor behaviors, has proven to be useful. This study aimed to investigate whether muscle synergy features could provid

Heel raise is widely prescribed to patients with chronic ankle instability in order to strengthen the Peroneus Longus muscle (PL) which supports the weakened lateral collateral ligaments. While the exercise itself is intuitive, ankle orientation is of particular importance because heel raises performed with inversion do not well recruit the PL. This implies that proper execution is imperative and a means to assess heel raise training sessions is needed. In this study we present a smart insole sy

Regulation of cell signaling through physical stimulation is an emerging topic in biomedicine. BACKGROUND: While recent advances in biophysical technologies show capabilities for spatiotemporal stimulation, interfacing those tools with biological systems for intact signal transfer and noncontact stimulation remains challenging. Here, we describe the use of a magnetic torque stimulation (MTS) system combined with engineered magnetic particles to apply forces on the surface of individual cells. MT

An FDA-approved soft wearable robot, the Myosuit, which was designed to provide hip and knee extension torque has recently been commercialized. While studies have reported reductions in metabolic costs, increased gait speeds, and improvements in clinical test scores, a comprehensive analysis of electromyography (EMG) signals and joint kinematics is warranted because the recruitment of appropriate muscle groups during physiological movement patterns facilitates effective motor learning. Here, we

Cognitive radio networks can be designed to manage the radio spectrum more efficiently by utilizing the spectrum holes in primary user's licensed frequency bands. The currently available unlicensed spectrum is reaching its limit and various demands for applications and data rates in wireless communications requires additional spectrum which imposes limits on spectrum access. These requirements demand for efficient and intelligent use of spectrum. The system model and the problem of the optimum s

Aiming at small high-speed rotating machines, this paper proposes a Lorentz force type self-bearing motor, where a new four-pole winding configuration is used to make it function both as a synchronous permanent-magnet motor and as a magnetic bearing. Due to using Lorentz force dominantly, the proposed motor has some good points such as linearity of control force and facility of design and analysis. And compared with the 8-pole type previously developed, it is advantageous at high speed. Focusing

Current gait rehabilitation strategies rely heavily on motor learning principles, which involve facilitating active patient participation, high-doses of biomechanical task-related motor activities and accurate feedback. Furthermore, appropriate muscle groups need to be recruited for the joint movements that constitute the biomechanical task-related activities in order to effectively promote motor learning. Recently, exoskeleton-type robots utilizing crutches have been incorporated into overgroun

Chronic ankle instability (CAI), due to its chronic nature and biomechanical complexity, is well-suited for continuous monitoring and tele-rehabilitation using wearable sensor technology. This study assessed whether a smart insole system, equipped with 4 force-sensing resistor sensors and an inertial measurement unit, combined with functional tests and biomechanical indices, could distinguish CAI patients from healthy controls. A total of 21 CAI patients (23.8 ± 5.1 years) and 16 controls (22.62

The lack of patient effort during robot‐assisted gait training (RAGT) is thought to be the main factor behind unsatisfactory rehabilitative efficacy among hemiparetic stroke patients. A key milestone to implement patient‐driven RAGT is to predict gait intent prior to actual joint movement. Here, the authors propose a method of predicting step speed intent via surface electromyogram (EMG) signals from the soleus. Six lower‐limb muscles were initially evaluated on a treadmill, and the results sugg

In this paper, performance of primary user detection based on fast Fourier transform (FFT) is analyzed and simulated for advanced television systems committee (ATSC) digital television (DTV) signals. In order to detect the present and absence of the ATSC DTV signals, a pilot detection scheme based on FFT is employed. A wireless communication channel is modeled as Gaussian channel. For evaluating the spectrum sensing performance, detection probability is derived. We consider four kinds of sensing

Abstract By using an adaptive threshold and weight based on the wavelet transform and Haar transform, a novel image enhancement algorithm is proposed. First, a medical image was decomposed with wavelet transform and all high-frequency sub-images were decomposed with Haar transform. Secondly, noise in the frequency domain was reduced by the proposed soft-threshold method. Thirdly, high-frequency coefficients were enhanced by the proposed weight values in different sub-images. Then, the enhanced i