• Journal of Biomedical Engineering Research
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• v.20 no.4
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• pp.471-477
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• 1999

Many researches have been performed whether electrical stimulation could be used for diagnosis and treatment on the auditory system impairment. Unfortunately, there were no standard methods or theoretical background for choosing stimulus conditions because of the lack of understanding on the transmission of electrical stimulation through the auditory pathway. This research was conducted to observe the effect of electrical stimulation on the tinnitus-induced animals. Nine guniea pigs were used for the experment and divided into two groups, five animals for the experimental group(A) and four animals for the control group(B). Experimental conditions were divided into four steps, before tinnitus induction and 1, 6, 12 hours after tinnitus induction using salicylate based on the Jastreboff model. In each experimental condition, ABR and ECochG were obtained, and autocorrelation coefficients were calculated from normalized waveforms based on rms values. Sum of all the autocorrelation coefficients was extracted as a parameter to observe the changes between before and after the electrical stimulation. As a result, ABR parameter values were rapidly increased 6 hours after tinnitus induction, the gradually returned back to the initial state. On the other hand, when electrical stimulation was applied, parameter values did not change compared with the initial sate. Parameter values of ECochG showed that the effect of electrical stimulation appeared 12 hours after the tinnitus induction. It was concluded that an electrical stimulation to the tinnitus-induced model changes the correlation coefficients of ABR and ECochG waveforms.

• Journal of the Korean Society of Radiology
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• v.6 no.2
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• pp.137-142
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• 2012

This study is investigated dose change on intra-oral radiography when same conditions under the others unit and same unit under the different exposed conditions. Three different radiation devices were studied. Exposure to the upper anterior, premolar and molar on the variant time and dose measure was using semiconductor radiation dose meter. Obtained film density value was analyzed to the belong in the range of diagnosis. Results for dose of each region were less dissimilar between the maximum and minimum. Its value was different 10 times as many as 3 times. In addition, the range of film density was 2.10 ~ 2.95. These values were exceeded on the allow density of diagnostic value '0.25 ~ 2.0'. Even if the same device and the same condition, measured dose was considerable differance and film density was showed show the inappropriate density range. Those can be caused the patient's re-take and patient's diagnostic errors so patients has affected direct and indirect radiological harm. Therefore, dental radiography devices will be required periodical maintenance and also provided standard on the exposure and processing conditions.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.19 no.11
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• pp.126-136
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• 2018

The purpose of this study was to develop a severity-adjustment model for predicting mortality in acute stroke patients using machine learning. Using the Korean National Hospital Discharge In-depth Injury Survey from 2006 to 2015, the study population with disease code I60-I63 (KCD 7) were extracted for further analysis. Three tools were used for the severity-adjustment of comorbidity: the Charlson Comorbidity Index (CCI), the Elixhauser comorbidity index (ECI), and the Clinical Classification Software (CCS). The severity-adjustment models for mortality prediction in patients with acute stroke were developed using logistic regression, decision tree, neural network, and support vector machine methods. The most common comorbid disease in stroke patients were hypertension, uncomplicated (43.8%) in the ECI, and essential hypertension (43.9%) in the CCS. Among the CCI, ECI, and CCS, CCS had the highest AUC value. CCS was confirmed as the best severity correction tool. In addition, the AUC values for variables of CCS including main diagnosis, gender, age, hospitalization route, and existence of surgery were 0.808 for the logistic regression analysis, 0.785 for the decision tree, 0.809 for the neural network and 0.830 for the support vector machine. Therefore, the best predictive power was achieved by the support vector machine technique. The results of this study can be used in the establishment of health policy in the future.

• Journal of Korean Neurosurgical Society
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• v.67 no.1
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• pp.84-93
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• 2024

Objective : We aimed to examine trends in critically ill neurology-neurosurgery (NNS) patients who were admitted to the intensive care unit (ICU) in South Korea and identify risk factors for in-hospital mortality after ICU admission in NNS patients. Methods : This nationwide population-based retrospective cohort study enrolled adult NNS adult patients admitted to the ICU from 2010 to 2019 extracted from the National Health Insurance Service in South Korea. The critically ill NNS patients were defined as those whose main admission departments were neurology or neurosurgery at ICU admission. The number of ICU admission, age, and total cost for hospitalization from 2010 to 2019 in critically ill NNS patients were examined as trend information. Moreover, multivariable logistic regression modeling was used to identify risk factors for in-hospital mortality among critically ill NNS patients. Results : We included 845474 ICU admission cases for 679376 critically ill NNS patients in South Korea between January 1, 2010 to December 31, 2019. The total number of ICU admissions among NNS patients was 79522 in 2010, which increased to 91502 in 2019. The mean age rose from 62.8 years (standard deviation [SD], 15.6) in 2010 to 66.6 years (SD, 15.2) in 2019, and the average total cost for hospitalization per each patient consistently increased from 6206.1 USD (SD, 5218.5) in 2010 to 10745.4 USD (SD, 10917.4) in 2019. In-hospital mortality occurred in 75455 patients (8.9%). Risk factors strongly associated with increased in-hospital mortality were the usage of mechanical ventilator (adjusted odds ratio [aOR], 19.83; 95% confidence interval [CI], 19.42-20.26; p<0.001), extracorporeal membrane oxygenation (aOR, 3.49; 95% CI, 2.42-5.02; p<0.001), and continuous renal replacement therapy (aOR, 6.47; 95% CI, 6.02-6.96; p<0.001). In addition, direct admission to ICU from the emergency room (aOR, 1.38; 95% CI, 1.36-1.41; p<0.001) and brain cancer as the main diagnosis (aOR, 1.30; 95% CI, 1.22-1.39; p<0.001) are also potential risk factors for increased in-hospital mortality. Conclusion : In South Korea, the number of ICU admissions increased among critically ill NNS patients from 2010 to 2019. The average age and total costs for hospitalization also increased. Some potential risk factors are found to increase in-hospital mortality among critically ill NNS patients.

• Journal of the Korean Data and Information Science Society
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• v.28 no.2
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• pp.339-348
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• 2017

One of the major issues of statistical process control for variables data is monitoring both the mean and the standard deviation. The traditional approach to monitor these parameters is to simultaneously use two seperate control charts. However there have been some works on developing a single chart using a single plotting statistic for joint monitoring, and it is claimed that they are simpler and may be more appealing than the traditonal one from a practical point of view. When using these control charts for variables data, estimating in-control parameters and checking the normality assumption are the very important step. Nonparametric Shewhart-Lepage chart, proposed by Mukherjee and Chakraborti (2012), is an attractive option, because this chart uses only a single control statistic, and does not require the in-control parameters and the underlying continuous distribution. In this paper, we introduce the Shewhart-Lepage chart, and propose the design procedure to find the optimal diagnosis limits when the location and the scale parameters change simultaneously. We also compare the efficiency of the proposed method with that of Mukherjee and Chakraborti (2012).

• Journal of the Korean Society of Radiology
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• v.1 no.3
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• pp.23-34
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• 2007

To find how much radiation was exposed the patients who visit emergency room, a measurement study was made for radiation amount toward 200 patients selected randomly among visitors to an emergency room in a university hospital from March 16 to 31st, 2006. The results are as follows ; 1. Among the subjects 50 person(25.0%) were transferred from other hospitals, 24 persons(8.3) come after traffic accident, 50 persons for other accident and 76 persons for general medical care. 2. The average frequency of X-ray taking was calculated as 6.4 time per person among transferred patients, 14.5 times per person among patients with traffic accident and 2.6 times per person among general medical care. 3. The radiation exposure amount by kind of X-ray showed 28.9mGyfor general X-ray diagnosis, 84.2mGy for CT scanning and 1.02mGy for other special radiation study. 4. Average radiation exposure amount was calculated as 24.6mGy by transferred patients, 55.2mGy by patients with traffic accident, 17.1mGy by patients with other accidents and 17.0mGy by general patients. 5. Through the comparison of radiation exposure amount among to subject with maximum allowance threshold by International Commission on X-ray Radium Protection, transferred patients exceeded 6 times than allowance in whole body except extremities and joints, blood forming organ, reproductive system, vitreous body of eye, bone, thyroid gland, skin and etc, Patient suffered from traffic accidents were exposed 10 times more than allowance. In conclusion, the radiation exposure amount during X-rat diagnosis re too much and exceeded allowance standard by International Commission on X-ray Radium Protection. So further study and preventive measure to decrease radiation exposure by patients who visit emergency room.

• The Journal of the Korea Contents Association
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• v.15 no.9
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• pp.411-417
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• 2015

To distinguish between HCC and HH is one of the important test methods in determining the treatment method by determining the treatment method by distinguishing malignant growth and benign tumors in liver CT scan. Currently, the specialist is reading CT images by their subjective judgment. So, the purpose of this study is to treat reading the CT images even more objective way. The test times after injection contrast medium in this study are the before injection phase(Pre.), artery phase(35sec), portal phase(70sec) and delay phase(180sec). The general pattern change of HCC in change of contrast enhancement pattern shows 26.6% matching. And the case of HH shows 16.6% matching. In order to observe the change of HU value between HCC and HH, each average values and standard deviation was confirm and as a result, it shows the lagre difference between artery and portal phase in lesion.(HCC$19.76{\pm}23.52$, HH$60.23{\pm}29.43$). And it shows the 76.6% matching in HCC and 80.0% matching in HH. Thorough this study, to suggest a HU value as objective analysis method and if the anlaysis method was used in clinical will assist in the diagnosis.

• Journal of radiological science and technology
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• v.28 no.2
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• pp.97-103
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• 2005

Objective : The aim of this study was to compare the knee joint displaying between the anteroposterior weight bearing(AP-WB) View and the metatarsophalangeal(MTP) view for assessing joint space narrowing(JSN) and osteophytes in osteoarthritis patients. Subjects and Materials : Two hundreds of twenty patients(38 men) who came rheumatoid caused by knee pain, had both AP-WB and MTP views taken on a day. Radiographs were evaluated independently by 13 experienced observers(3 orthopedics surgeon, 2 rheumatogist, 3 radiologist, 5 radiological technologist) They assessed JSN and osteophytes using by PACS monitor JSN was scored by the optic evaluation to the nearest at the narrowest point in medial compartments of the tibiofemoral joint in both knees. Osteophytes were graded 0 to 3(bad 0, not bad 1, good 2 and very good 3) according to a standard atlas. All exam was using by Philips(Buckey Diagnostic-TH) X-ray material. Exposure condition was 60 kv, 8 mAs and 100 cm focus to film distance. Results : JSN was scored $1.32{\pm}0.050$ in AP-WB view, $2.51{\pm}0.046$ in MTP view. MTP view of JSN score is higher to AP-WB view significantly(p<0.05). Osteophytes scored $2.14{\pm}0.054$ in AP-WB view, $2.10{\pm}0.054$ in MTP view. There was no difference(p<0.05) between MTP view and AP-WB view in osteophytes. But MTP view was more reproducible than AP-WB view Conclusions : Joint space narrowing is most important factor to diagnosis with knee joint Osteoarthritis patients. This study was summarized as follows; In comparision of JSN, MTP view was more widely displayed than AP-WB view. In comparision of Osteophytes, there was no difference between MTP view and AP-WB view. It was concluded MTP view was more useful method to diagnosis of knee joint Osteoarthritis patients.

• Journal of Preventive Medicine and Public Health
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• v.11 no.1
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• pp.123-127
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• 1978

The major objective of this research is to identify those hospital characteristics that best explain cost variation among hospitals and to formulate linear models that can predict hospital costs. Specific emphasis is placed on hospital output, that is, the identification of diagnosis related patient groups (DRGs) which are medically meaningful and demonstrate similar patterns of hospital resource consumption. A casemix index is developed based on the DRGs identified. Considering the common problems encountered in previous hospital cost research, the following study requirements are estab-lished for fulfilling the objectives of this research: 1. Selection of hospitals that exercise similar medical and fiscal practices. 2. Identification of an appropriate data collection mechanism in which demographic and medical characteristics of individual patients as well as accurate and comparable cost information can be derived. 3. Development of a patient classification system in which all the patients treated in hospitals are able to be split into mutually exclusive categories with consistent and stable patterns of resource consumption. 4. Development of a cost finding mechanism through which patient groups' costs can be made comparable across hospitals. A data set of Medicare patients prepared by the Social Security Administration was selected for the study analysis. The data set contained 27,229 record abstracts of Medicare patients discharged from all but one short-term general hospital in Connecticut during the period from January 1, 1971, to December 31, 1972. Each record abstract contained demographic and diagnostic information, as well as charges for specific medical services received. The 'AUT-OGRP System' was used to generate 198 DRGs in which the entire range of Medicare patients were split into mutually exclusive categories, each of which shows a consistent and stable pattern of resource consumption. The 'Departmental Method' was used to generate cost information for the groups of Medicare patients that would be comparable across hospitals. To fulfill the study objectives, an extensive analysis was conducted in the following areas: 1. Analysis of DRGs: in which the level of resource use of each DRG was determined, the length of stay or death rate of each DRG in relation to resource use was characterized, and underlying patterns of the relationships among DRG costs were explained. 2. Exploration of resource use profiles of hospitals; in which the magnitude of differences in the resource uses or death rates incurred in the treatment of Medicare patients among the study hospitals was explored. 3. Casemix analysis; in which four types of casemix-related indices were generated, and the significance of these indices in the explanation of hospital costs was examined. 4. Formulation of linear models to predict hospital costs of Medicare patients; in which nine independent variables (i. e., casemix index, hospital size, complexity of service, teaching activity, location, casemix-adjusted death. rate index, occupancy rate, and casemix-adjusted length of stay index) were used for determining factors in hospital costs. Results from the study analysis indicated that: 1. The system of 198 DRGs for Medicare patient classification was demonstrated not only as a strong tool for determining the pattern of hospital resource utilization of Medicare patients, but also for categorizing patients by their severity of illness. 2. The wei틴fed mean total case cost (TOTC) of the study hospitals for Medicare patients during the study years was $11,27.02 with a standard deviation of $117.20. The hospital with the highest average TOTC ($1538.15) was 2.08 times more expensive than the hospital with the lowest average TOTC ($743.45). The weighted mean per diem total cost (DTOC) of the study hospitals for Medicare patients during the sutdy years was $107.98 with a standard deviation of $15.18. The hospital with the highest average DTOC ($147.23) was 1.87 times more expensive than the hospital with the lowest average DTOC ($78.49). 3. The linear models for each of the six types of hospital costs were formulated using the casemix index and the eight other hospital variables as the determinants. These models explained variance to the extent of 68.7 percent of total case cost (TOTC), 63.5 percent of room and board cost (RMC), 66.2 percent of total ancillary service cost (TANC), 66.3 percent of per diem total cost (DTOC), 56.9 percent of per diem room and board cost (DRMC), and 65.5 percent of per diem ancillary service cost (DTANC). The casemix index alone explained approximately one half of interhospital cost variation: 59.1 percent for TOTC and 44.3 percent for DTOC. Thsee results demonstrate that the casemix index is the most importand determinant of interhospital cost variation Future research and policy implications in regard to the results of this study is envisioned in the following three areas: 1. Utilization of casemix related indices in the Medicare data systems. 2. Refinement of data for hospital cost evaluation. 3. Development of a system for reimbursement and cost control in hospitals.

• Journal of Korean society of Dental Hygiene
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• v.11 no.3
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• pp.325-341
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• 2011

Objectives : This research has investigated the reality of the education of the claim and the degree of the education for the claimed of the dentistry recuperation organization in the Daejeon and Chuncheong are for the improvement of the problem in the medical expenses. Methods : It use as a basic data for the vitalizations of the education and performed the survey in the dentistry recuperation organization in the Daejeon and ChungCheong Nam BukDo which are registered in the evaluating organization for judging the health insurance in the present May 2010, and concluded just like the below. Results : 1. The education of the claim in the requirer in the dentistry recuperation organization, and the education of the claim was especially lacking when the dentist was studying in the university, and the dental hygienist had the similar educational experience in the school and the clinic (p<0.05) 2. Most of the requirer in the dental recuperation organization was hoping to get the education related to the claim work, but the dentist and the nurse's aid was relatively low (p<0.05) 3. For fixing the error of the claim, the participation and the extension of the judging standard of the insurance was the highest among the university subordinate dental hospital/dental hospital, but the health center was relatively low (p<0.05). 4. The dentist feels the economic burden in employing the special employee because the raising of the special judging people, compared to others, but the staffs such as the dental hygienist preferred it as one of ways to fix the error of the claim of the dental insurance (p<0.05) 5. Both dentists and the dental hygienist said proper time to teach the insurance was all needed in the school, and the clinic, but other workers relatively believed it should be held in the clinic (p<0.05). 6. The important factors to decide the participation of the lecture was in order of the contents of the lecture, the place of the lecture, the amount for the lecture, the superintendent of the lecture, whether it has gone through the educational score, and whether it has passed the conserving educational score was relatively less important in the university subordinate dentist/dentist, but the medical center was very effective as 4.50 (p<0.05) 7. Health Insurance Review and assessment service was very high as the managing department for supplying the lecture and the information, 70.5%, and the next was the Korean Dental Association/ Korean dental hygiene association, but dentists were preferring the association to manage in than the Health Insurance Review and assessment service to manage (p<0.05) 8. In preferring lecture for the inquiring the insurance, periodontal surgery was the highest as 4.51, the diagnosis standard for injection was high in the university subordinate hospital/dentists, and the more the year of the insurance inquiry, the less the doctor who was hoping for the lecture about the basic treatment. Conclusions : Taken together, it is decided that the inquiry education about the medical expense in the dentist, so the consistent and systematic education should be held to the related people, and from this, it is thought to reduce the problem of the inquiry of the medical expenses by fostering the knowledge and supplying the information which are related to the inquiry of the dentists.