Sungmin Park

PURPOSE: To develop and demonstrate a method to calculate the temperature rise that is induced by the radio frequency (RF) field in MRI at the electrode of an implanted medical lead. MATERIALS AND METHODS: The electric field near the electrode is calculated by integrating the product of the tangential electric field and a transfer function along the length of the lead. The transfer function is numerically calculated with the method of moments. Transfer functions were calculated at 64 MHz for dif

Purpose To investigate relationships between teamwork, trust and teacher team commitment. Design/methodology/approach Research has confirmed the value‐added effects of organizational commitment in terms of job performance, organizational effectiveness, and employee retention. This study focused on teacher teams as the unit of analysis, and posited associations between teamwork, viewed as team skills, trust and teacher team commitment. Data were derived from responses of elementary school teacher

Wearable pressure sensors have demonstrated great potential in detecting pulse pressure waves on the skin for the noninvasive and continuous diagnosis of cardiac conditions. However, difficulties lie in positioning conventional single-point sensors on an invisible arterial line, thereby preventing the detection of adequate signal amplitude for accurate pulse wave analysis. Herein, we introduce the spatiotemporal measurements of arterial pulse waves using wearable active-matrix pressure sensors t

Article Battery capacity measurement and analysis using lithium coin cell battery Share on Authors: Sung Park Networked and Embedded Systems Laboratory, Electrical Engineering Departments, University of California, Los Angeles Networked and Embedded Systems Laboratory, Electrical Engineering Departments, University of California, Los AngelesView Profile , Andreas Savvides Networked and Embedded Systems Laboratory, Electrical Engineering Departments, University of California, Los Angeles Networke

Human neuron-specific RNA-binding protein HuD belongs to the family of Hu proteins and consists of two N-terminal RNA recognition motifs (RRM1 and -2), a hinge region, and a C-terminal RRM (RRM3). Hu proteins can bind to AU-rich elements in the 3' untranslated regions of unstable mRNAs, causing the stabilization of certain transcripts. We have studied the interaction between HuD and prototype mRNA instability elements of the sequence UU(AUUU)(n)AUU using equilibrium methods and real-time kinetic

BACKGROUND: For an effective artificial pancreas (AP) system and an improved therapeutic intervention with continuous glucose monitoring (CGM), predicting the occurrence of hypoglycemia accurately is very important. While there have been many studies reporting successful algorithms for predicting nocturnal hypoglycemia, predicting postprandial hypoglycemia still remains a challenge due to extreme glucose fluctuations that occur around mealtimes. The goal of this study is to evaluate the feasibil

Unmanaged long-term mental stress in the workplace can lead to serious health problems and reduced productivity. To prevent this, it is important to recognize and relieve mental stress in a timely manner. Here, we propose a novel stress detection algorithm based on end-to-end deep learning using multiple physiological signals, such as electrocardiogram (ECG) and respiration (RESP) signal. To mimic workplace stress in our experiments, we used Stroop and math tasks as stressors, with each stressor

In this paper, we look at different battery capacity models that have been introduced in the literatures. These models describe the battery capacity utilization based on how the battery is discharged by the circuits that consume power. In an attempt to validate these models, we characterize a commercially available lithium coin cell battery through careful measurements of the current and the voltage output of the battery under different load profile applied by a micro sensor node. In the result,

We previously showed that plasma gelsolin, a major component of the extracellular actin scavenging system, is an matrix metalloproteinase (MMP)-14 substrate. Here we confirmed that plasma gelsolin is cleaved by MMP-14 at the plasma level, and found that it was most efficiently digested by MMP-3 followed by MMP-2, MMP-1, MMP-14, and MMP-9, in that order. Plasma gelsolin (90 kDa) was cut into several fragments of 43-48 kDa by MMP-3. The MMP-3 cleavage sites in plasma gelsolin were determined by la

To overcome a world-wide water shortage problem, numerous desalination methods have been developed with state-of-the-art power efficiency. Here we propose a spontaneous desalting mechanism referred to as the capillarity ion concentration polarization. An ion-depletion zone is spontaneously formed near a nanoporous material by the permselective ion transportation driven by the capillarity of the material, in contrast to electrokinetic ion concentration polarization which achieves the same ion-dep

Implantable medical devices (IMDs) enable patients to monitor their health anytime and receive treatment anywhere. However, due to the limited capacity of a battery, their functionalities are restricted, and the devices may not achieve their intended potential fully. The most promising way to solve this limited capacity problem is wireless power transfer (WPT) technology. In this study, a WPT based implantable electrocardiogram (ECG) monitoring device that continuously records ECG data has been

Several studies have investigated the use of invasive and non-invasive stimulation methods to enhance nerve regeneration, and varying degrees of effectiveness have been reported. However, due to the use of different parameters in these studies, a fair comparison between the effectiveness of invasive and non-invasive stimulation methods is not possible. The present study compared the effectiveness of invasive and non-invasive stimulation using similar parameters. Eighteen Sprague Dawley rats were

Abstract In implantable bioelectronics, which aim for semipermanent use of devices, biosafe energy sources and packaging materials to protect devices are essential elements. However, research so far has been conducted in a direction where they cannot coexist. Here, the development of capacitance‐matched triboelectric implants driven is reported by ultrasound under 500 mW cm −2 safe intensity and realize a battery‐free, miniatured, and wireless neurostimulator with full titanium (Ti) packaging. T