• Analytical Science and Technology
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• v.28 no.6
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• pp.425-429
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• 2015

A cholesterol biosensor was developed using a modified carbon electrode with carbon nanotubes. The disposable cholesterol biosensor was modified with carbon nanotubes to enhance electron transfer during the enzymatic reaction of cholesterol. Cholesterol oxidase and peroxidase, with potassium ferrocyanide as a mediator, were immobilized on a screen-printed carbon nanotube electrode. The electrochemical cholesterol biosensor developed using carbon nanotubes showed a rapid and reliable signal for measuring total cholesterol. The cholesterol sensor showed a linear response in 5 seconds with a small volume (0.5 μL) in the range of 100~400 mg/dL, with a coefficient of variation of 4.0%.

• Korea-Australia Rheology Journal
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• v.17 no.1
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• pp.9-13
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• 2005

The aggregation of red blood cells (RBCs) is a major determinant of blood flow resistance passing through various veins. Available techniques for measuring RBC aggregation often require pretreating and washing after each measurement, which is not optimal for day-to-day clinical use. A laser reflection technique has been combined with a vibration-aided disaggregation mechanism, which shows significant advances in aggregometer design, operation and data analysis. The essential features of this design are in its simplicity and a disposable element that is in contact with the blood sample. Using extremely small quantities of blood, the RBCs subjected to vibrations can be quickly and completely disaggregated. This is followed by measuring the backscattered light intensity. The measurements with the present sensor were compared with those of a commercial aggregometer and a strong correlation was found between them. The newly-developed optical aggregometer can measure the RBC aggregability difference between young and old cell suspension with ease and accuracy.

• Journal of Sensor Science and Technology
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• v.27 no.5
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• pp.340-344
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• 2018

Electrodes are an important part of electrocardiography (ECG); disposable electrodes have been extensively used. However, personal ECG monitoring devices for Internet of Things applications require reusable electrodes. As there have been no systematic studies on the characteristics of reusable electrodes to date, we conducted this study to assess the performance and feasibility of electrodes with different materials. We built reusable electrodes using twelve different metallic materials, including commonly used copper, silver, zinc, plating materials, chemically inert titanium, stainless steel, and aluminum. Each electrode was fabricated to a size of $5{\times}10mm$. Their characteristics such as offset, baseline drift, stabilization time, and chemical inertness were compared. A personal ECG monitoring system was used to test the manufactured electrodes. The performances of the Ag, Cu, and Zn electrodes were better than the performances of other electrodes. However, these materials may not be used owing to the chemical changes that occur when the electrodes are in contact with the skin, such as discoloration and corrosion, which deteriorate their electrical characteristics. Titanium, stainless steel, and aluminum are chemically stable. The titanium electrode showed the best performance among the three, and it is our recommendation as a material for manufacturing reusable electrodes.

• Journal of Sensor Science and Technology
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• v.14 no.4
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• pp.250-257
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• 2005

Respiratory tubes with the length of 35 mm and the diameter of 10, 15, and 20 mm were made and both the static($P_{S}$) and dynamic($P_{D}$) pressures were measured for steady flow rates ranging 1-12 l/sec. Regression analysis resulted successful fitting of $P_{S}$ and $P_{D}$ data with quadratic equations with correlation coefficients higher than 0.99. The measurement standards of the American Thoracic Society (ATS) were applied to $P_{S}$ data, which demonstrated the smallest tube diameter of 15 mm to satisfy the ATS standards. The maximum $P_{D}$ value of the velocity type transducer with the diameter of 15 mm was estimated to be 75 cm$H_{2}O$, implying approximately 7 times larger sensitivity than the widely used pneumotachometer. These results showed that the velocity type respiratory air flow transducer is a unique device accomplishing miniaturization with the sensitivity increased, thus would be of great advantage to develop portable devices.

• KSBB Journal
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• v.10 no.4
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• pp.468-474
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• 1995

The disposable glucose bio-sensor using composite of CTA and PCL membrane was developed for measurement of glucose. The most effective membrane was composed of CTA/PCL(80/20, w/w) and glutaraldehyde one-step immobilization method ($10{\mu}m$ thickness) for glucose sensor gave the best result among various methods, considering oxygen permeability and electronic sensitivity. A scanning electron micrograph of the cross-section of a typical asymmetric CTA/PCL composite membrane showed that the membrane fused with a dense layer covered with a GOD-glutaraldehyde. Glucose oxidase immoblilized on the membrane showed the linearity between difference of absolute amperometric values and glucose concentrations within 7mM when the GOD immobilized electrode was used. About 35% of activity was remained after 8 days when the tyrosinase was immobilized on CTA/PCL (80/20) membrane.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2006.05a
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• pp.1023-1026
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• 2006

There are some cases in trouble with monitoring emergency patient by existing electrode sensor in measuring instrument in home and hospital etc. And there are problem to measure because of coming down electrode in emergency car or vessel of shaking and fat, humidity of patient. In this study, it has designed band-type for patient to put on the breast easily and go around anywhere freely putting band electrode on his body. Gold has used as electrode material in this electrocardiogram because of its excellent electronic resistance peculiarity and no trouble with skin. And it is able to monitor multi-body-signal by additional design of periphery temperature. There are good results of body signal transmission in the breast or the rib, and get a little body signal in abdomen. We get a result it is better case of gold than usual electrode on signal detection, and know usual electrode was disposable, but we have more correct result from gold electrode sensor, being semi-permanent ana. great contact ability even if movement.

• Journal of the Korean Society of Clothing and Textiles
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• v.34 no.1
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• pp.112-125
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• 2010

A Holter monitor is used for ECG monitoring of ambulatory daily life in hospital. However, the use of this apparatus causes skin allergies and discomfort in patients because of the attachment gel and tapes used to attach disposable electrodes to the skin. In this study, the development of tight-fitting clothing connected to a portable Holter monitor was proposed. In addition, the use of conductive fabrics as electrodes was proposed; this will enable the use of garments in u-health care for measuring ECG signals. The male subjects were university students in the ages of 20 to 24. Subjective wear sensations of the experimental garments were rated using seven Likert scales. A Likert type scale was used for the evaluation and a 7 point score indicates that it provided the best fit as a tight-fitting upper clothing. Clothing pressure was measured using an air-pack-type pressure sensor (model AMI 3037-2) at 4 locations (the conductive fabric electrode) As results, a male basic sloper for upper clothing was developed and that pattern was manipulated to the tight fit pattern by considering the reduction rate of the percentage stretch in the fabric. The developed tight-fitting garment was superior in terms of subjective sensation and 6t. The mean pressure of the garment with reduction rates of 40% in width and of 50% in length was 8.45gf/$cm^2$. A conductive fabric electrode was developed by considering the sewing method and the developed electrode was detected well. The ECG data were recorded for 13 hr 19 min 44 sec and the artifacts in the ECG signals were recorded for 9 hr 3 min 46 sec (total time: 22 hr 23 min 23 sec). The artifacts data were obtained during heavy activities.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2016.05a
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• pp.331-335
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• 2016

When a boating accident, such as a January number three, the customer's risk management issues emerged. Ships and accident risk in confined spaces such as risk management to locate the customer and dangers of probation is available. In this paper, aboard after consent to obtain information for customers to wrist to customers, webbing or portable device embedded in devices and Wireless sensor information Input was attached, disposable consumer information. Customer on board the ship setting for location analysis and positioning according to information communication protocol, ships, each customer's real-time location information on the screen, 3 the foundation of d customers on the floor Can be designed to inform. Threshold designed to reduce the error of the information to analyze the position in current position and errors. Also, to system attacks would control the situation of accident and emergency jaenanguk server with real-time information transmission of information outside the emergency during a disaster, search and Disaster relief to be possible.

• Applied Chemistry for Engineering
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• v.32 no.6
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• pp.684-689
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• 2021

In this paper, we develop a cost effective and disposable voltammetric sensing platform involving screen-printed carbon electrode (SPCE) modified with the nanocomposites composed of multi-walled carbon nanotubes, polyelectrolyte, and tyrosinase for bisphenol A. This is known as an endocrine disruptor which is also related to chronic diseases such as obesity, diabetes, cardiovascular and female reproductive diseases, precocious puberty, and infertility. A negatively charged oxidized multi-walled carbon nanotubes (MWCNTs) wrapped with a positively charged polyelectrolyte, e.g., polydiallyldimethylammonium, was first wrapped with a negatively charged tyrosinae layer via electrostatic interaction and assembled onto oxygen plasma treated SPCE. The nanocomposite modified SPCE was then immersed into different concentrations of bisphenol A for a given time where the tyrosinase reacted with OH group in the bisphenol A to produce the product, 4,4'-isopropylidenebis(1,2-benzoquinone). Cyclic and differential pulse voltammetries at the potential of -0.08 V vs. Ag/AgCl was employed and peak current changes responsible to the reduction of 4,4'-isopropylidenebis(1,2-benzoquinone) were measured which linearly increased with respect to the bisphenol A concentration. In addition, the SPCE based sensor showed excellent selectivity toward an interferent agent, bisphenol S, which has a very similar structure. Finally, the sensor was applied to the analysis of bisphenol A present in an environmental sample solution prepared in our laboratory.

• Applied Chemistry for Engineering
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• v.34 no.3
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• pp.258-263
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• 2023

In this study, conductive polymers and the enzyme tyrosinase (Tyr) were deposited on the surface of a screen printed carbon electrode (SPCE), which can be fabricated as a disposable sensor chip, and applied to the detection of bisphenol F (BPF), an endocrine disruptor with proven links to male diseases and thyroid disorders, using electrochemical methods. On the surface of the SPCE working electrode, which was negatively charged by oxygen plasma treatment, a positively charged conductive polymer, poly(diallyldimethyl ammonium chloride) (PDDA), a negatively charged polymer compound, poly(sodium 4-styrenesulfonate) (PSS), and another layer of PDDA were layered by electrostatic attraction in the order of PDDA, PSS, and finally PDDA. Then, a layer of Tyr, which was negatively charged due to pH adjustment to 7.0, was added to create a PDDA-PSS-PDDA-Tyr sensor for BPF. When the electrode sensor is exposed to a BPF solution, which is the substrate and target analyte, 4,4'-methylenebis(cyclohexa-3,5-diene-1,2-dione) is generated by an oxidation reaction with the Tyr enzyme on the electrode surface. The reduction process of the product at 0.1 V (vs. Ag/AgCl) generating 4,4'-methylenebis(benzene-1,2-diol) was measured using cyclic and differential pulse voltammetries, resulting in a change in the peak current with respect to the concentration of BPF. In addition, we compared the detection performance of BPF using an ionic liquid electrolyte as an alternative to phosphate-buffered saline, which has been used in many previous sensing studies. Furthermore, the selectivity of bisphenol S, which acts as an interfering substance with a similar structure to BPF, was investigated. Finally, we demonstrated the practical applicability of the sensor by applying it to analyze the concentration of BPF in real samples prepared in the laboratory.