• Tuberculosis and Respiratory Diseases
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• v.48 no.5
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• pp.773-780
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• 2000

Background : pH measurement is an important test in assessing the etiology of pleurisy and in identifying complicated parapneumonic effusion. Although the blood gas analyzer is the gold standard method' for pleural pH measurement, pH meter & pH strip methods are also used for this purpose interchangably. However, the correlation among the pH data measured by the three different methods needs to be evaluated. In this study, we measured the pH of pleural fluid with the three different methods respectively and evaluated the correlation among the measured data. Methods : From August 1999 to March 2000, we measured the pleural fluid pH in 34 clinical samples with three methods-blood gas analyzer, pH meter, and pH strip. In the blood gas analyzer and pH meter methods, the temperature of pleural fluid was maintained around $0^{\circ}C$ in air-tight condition before analysis and measurement was performed within 30 minutes after collection. As for the pH strip method, the pleural fluid pH was checked in the ward immediately after tapping and in the clinical laboratory of our hospital. This part is unclear. Results : The causes of pleural effusion were tuberculosis pleurisy in 16 cases, malignant pleural effusion 5 cases, parapneumonic effusion 9 cases, empyema 3 cases, and congestive heart failure 1 case. The pH of pleural fluid (mean$\pm$SD) was 7.34$\pm$0.12 with blood gas analyser, 7.52$\pm$0.25 with pH meter, 7.37$\pm$0.16 with pH strip of immediate measurement and 6.93$\pm$0.201 with pH strip of delayed measurement. The pH measured by delayed pH strip measurement was lower than those of other methods (p<0.05). The correlation of the results between the blood gas analyzer and pH meter(p=0.002, r=0.518) and the blood gas analyzer and pH strip of immediate measurement(p<0.001, r=0.607). Conclusion : In the determination of pH of pleural fluid, pH strip method could be a simple and reliable method under immediate measurement conditions after pleural fluid tapping.

• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.301-304
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• 1988

A pH-meter has been newly developed by using on ISFET as the ion sensing element. The performance characteristics of the developed pH-meter have been investigated and confirmed to be used practically. The stable operation and the temperature compensation were stressed in this study.

• Journal of Oral Medicine and Pain
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• v.40 no.3
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• pp.124-129
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• 2015

Purpose: Salivary pH is an easily measurable biochemical marker and related to various intraoral and systemic conditions. The aim of this study was to evaluate the reliability of the salivary pH measurement using pH paper. In addition, the normal values of salivary pH using pH paper were compared to those of pH meter to investigate the validity. Methods: Twenty healthy male participants attended this study (mean age, $24.5{\pm}1.47$ years). Unstimulated saliva and stimulated saliva were collected from each subject two times with the interval of a day and salivary pH was immediately measured by the two experienced examiners using pH paper and pH meter. The salivary pH was compared between the groups and inter- and intra-examiner reliability of pH paper was investigated. The intraclass correlation coefficient (ICC) was used to calculate variations. Results: All measurements had good to excellent inter-examiner (ICC 0.755 for unstimulated; 0.760 for stimulated saliva), intra-examiner (ICC 0.635 for unstimulated; 0.592 for stimulated saliva) reliability and two measurement methods using pH paper and pH paper also showed high reliability (ICC 0.852 for unstimulated; 0.640 for stimulated saliva). The values measured by pH paper were significantly lower than those measured by pH meter. Conclusions: pH paper showed adequate inter- and intra-examiner reliability and it presented the validity in terms of comparison with the pH meter as a standard in the salivary pH measurement.

• Journal of Sensor Science and Technology
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• v.6 no.2
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• pp.131-136
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• 1997

The ISFET(ion sensitive field effect transistor), a semiconductor ion sensor, has many advantages over conventional ion sensors. Various single-sensor type ISFET pH-meters have been developed. However, they could not be applied in fields because their performances are directly affected by the sensor condition. With only one sensor, the system could be easily damaged from environmental factors, and reliability of it is decreased. Therefore, a 4-channel PH-meter system is proposed to improve the reliability of ISFET pH-meter. It has 4 ISFETS as ion sensor, and a software which contains a new calibration and measurement algorithm appropriate to the system. The reliability of the system was proved by measuring hydrogen ion concentration in the pH standard solutions and buffer solutions.

• Journal of Biomedical Engineering Research
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• v.38 no.6
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• pp.277-284
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• 2017

This paper presents an implantable pH measurement electrode for wireless gastroesophageal reflux measurement. Usually, gastroesophageal reflux is diagnosed by a catheter-type wire connection between the esophagus and the diagnostic device which brings many side effects such as restriction of daily living, pain, and discomfort in the nasal cavity and pharynx of patients. In order to solve these issues, researchers have been studied a wireless measurement method and a micro-sized pH electrode for human body insertion is necessary. Commercial glass packaged pH meter is formed by a sensing and a reference electrodes in a KCl solution. However, if the glass meter is inserted into the human body, there are risks of leakage of the solution, breakage of the glass package, injury of the body elements. Therefore, the solution should be solidified on the micro-sized noble metal wire which has a characteristic of biocompatible. After solidified wire fabrication, the designed meter was tested for feasibility of measurement and the result was well agreed with pH values of commercial pH meter. Potentials in pH 1 to 12 solution was measured to obtain the sensitivity of the sensor with linearity. And we have designed a simulation of gastroesophageal reflux with symptom frequency, interval, and duration time in pH 2 solution. The proposed sensor has capable to get the same potential for 24 measurements in 3 days, and it has sensed same pH values of 2 for one hour with every 10 minutes. Furthermore, the sensor was survived for 48 hours with reasonable potentials in the acid solution.

• Journal of Korean Academy of Fundamentals of Nursing
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• v.17 no.3
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• pp.314-323
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• 2010

Purpose: This study was performed to identify skin hydration status and skin surface pH according to the body parts of the aged with immobilization. Methods: The subjects were 101 aged patients in a hospital and a institution for the elderly in Seoul. Data for skin hydration and skin surface pH were collected using corneo-meter and skin pH-meter. The body parts of measurement were 10 parts; face, forearm, back of the hand, flank, upper abdomen, leg, back of the foot, heel, scapular, and sacrum. The data were analyzed by SPSS/WIN 12.0 program. Results: Skin hydration status were relatively low especially on lower extremity and back of body, and skin surface pH of scapular and sacrum were high. There was significant negative correlation between skin hydration status and skin surface pH on the 6 body parts. Conclusion: Skin hydration status and skin surface pH, especially on scapular, sacrum, and lower extremity need to be considered as important control factors for increasing skin health status of the aged with immobilization.

• Textile Coloration and Finishing
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• v.5 no.4
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• pp.92-100
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• 1993

1.8 기능성 색소 1.8.1 pH 지시약 수용액 중의 수소 이온 농도 [H$\^$+/]([]는 농도를 의미한다)를 간단하게 조사하기 위해 pH지시약을 이용하고 있다. 지시약은 일반적으로 유기약산이라든지 약염기로 용액의 pH에 의존하여 수소 이온(프로톤)이나 수산화물 이온이 부가된다든지 탈리 한다든지하여 색이 변화한다. [H$\^$+/]의 값은 작기 때문에 pH = -log[H$\^$+/]의 값으로 표시하며, pH 지시약에 담근 시험지나 pH meter로 측정한다. 예를 들면 페놀프탈레인은 무색의 약산으로 [HIn]으로 표시된다. 그 수용액은 조금만 전리하며, 그 공역 염기 [In$\^$-/]은 적색을 띈다.

• Investigative Magnetic Resonance Imaging
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• v.18 no.1
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• pp.52-58
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• 2014

Purpose : To establish a pH measurement system for a mouse tumor study using a clinical scanner, to develop the $^1H$ and 31P radio frequency (RF) coil system and to test pH accuracy with phantoms. Materials and Methods: The $^1H$ and the $^{31}P$ surface coils were designed to acquire signals from mouse tumors. Two coils were positioned orthogonally for geometric decoupling. The pH values of various pH phantoms were calculated using the $^1H$ decoupled $^{31}P$ MR spectrum with the Henderson-Hasselbalch equation. The calculated pH value was compared to that of a pH meter. Results: The mutual coil coupling was shown in a standard $S_{12}$. Coil coupling ($S_{12}$) were -73.0 and -62.3 dB respectively. The signal-to-noise ratio (SNR) obtained from the homogeneous phantom $^1H$ image was greater than 300. The high resolution in vivo mice images were acquired using a $^{31}P$-decoupled $^1H$ coil. The pH values calculated from the $^1H$-decoupled $^{31}P$ spectrum correlated well with the values measured by pH meter ($R^2$=0.97). Conclusion: Accurate pH values can be acquired using a $^1H$-decoupled $^{31}P$ RF coil with a clinical scanner. This two-surface coil system could be applied to other nuclear MRS or MRI.

• 월간산업보건
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• s.85
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• pp.25-31
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• 1995

• Journal of Veterinary Clinics
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• v.18 no.4
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• pp.363-367
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• 2001

Shampoos are used routinely by a large number of veterinarians to treat skin diseases. Skin pH is affected by shampoos, however, known to occur. In order to evaluate the effect of shampoos on skin surface pH, we performed the measurement of skin pH using skin pH meter PH900 in five healthy mixed breed dogs. The seven commercial shampoos: Humilac, Sebocalm, Sebolytics, Etiderm, PEroxyderm, HyLyt and Zn-7 Derm were included in this study. The anatomical sites, right thorax was the highest pH (7.66$\pm$0.10), and the lowest pH (6.20$\pm$0.23) was left pinna. A statiscally significant decrease in skin pH was found 7 minutes after application of Humilac, Sebocalm, Etiderm, Peroxyderm (p<0.01) and Sebolytics (p<0.05). After 17 minutes of application skin surface pH was inclined to increase in every shampoos but the degree of increase was slight at 77 minutes. No statiscally significant differences were found in HyLy-T and Zn-7 Derm, but skin pH was normal range (6.2-7.8) after application. Throughout the experiment skin surface pH was maintained above pH 7.0 in detergent. The commercial shampoos, Humilac, Sebocalm, Etiderm, had the decreasing effect on skin surface pH in dogs. The other four shampoos maintain the skin pH normal range. The skin pH meter PH 900 was found simple and useful for skin pH measurement.