• Progress in Medical Physics
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• v.29 no.4
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• pp.123-136
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• 2018

The complex dose distribution and dose transfer characteristics of intensity-modulated radiotherapy increase the importance of precise beam data measurement and review in the acceptance inspection and preparation stages. In this study, we propose a process map for the introduction and installation of high-precision radiotherapy devices and present items and guidelines for risk management at the acceptance test procedure (ATP) and commissioning stages. Based on the ATP of the Varian and Elekta linear accelerators, the ATP items were checked step by step and compared with the quality assurance (QA) test items of the AAPM TG-142 described for the medical accelerator QA. Based on the commissioning procedure, dose quality control protocol, and mechanical quality control protocol presented at international conferences, step-by-step check items and commissioning guidelines were derived. The risk management items at each stage were (1) 21 ionization chamber performance test items and 9 electrometer, cable, and connector inspection items related to the dosimetry system; (2) 34 mechanical and dose-checking items during ATP, 22 multileaf collimator (MLC) items, and 36 imaging system items; and (3) 28 items in the measurement preparation stage and 32 items in the measurement stage after commissioning. Because the items presented in these guidelines are limited in terms of special treatment, items and practitioners can be modified to reflect the clinical needs of the institution. During the system installation, it is recommended that at least two clinically qualified medical physicists (CQMP) perform a double check in compliance with the two-person rule. We expect that this result will be useful as a radiation safety management tool that can prevent radiation accidents at each stage during the introduction of radiotherapy and the system installation process.

• Journal of Gastric Cancer
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• v.23 no.3
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• pp.451-461
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• 2023

Purpose: Endoscopic submucosal dissection (ESD) is an effective treatment for early gastrointestinal neoplasms. However, this is a time-consuming procedure requiring various devices. This study aimed to evaluate the efficacy and safety of the ClearCut^TM Knife H-type, which is an integrated needle-tipped and insulated-tipped (IT) knife. Materials and Methods: Between July 2020 and September 2021, 99 patients with gastric epithelial neoplasms scheduled for ESD at three tertiary care hospitals were randomly assigned to H-knife (ClearCut^TM Knife H-type) or IT-knife (conventional IT knife) groups. Procedure times, therapeutic outcomes, and adverse events were analyzed. Results: A total of 98 patients (50 in the H-knife group and 48 in the IT-knife group) were analyzed. The median total procedure time was 11.9 minutes (range, 4.4-47.2 minutes) in the H-knife group and 12.7 minutes (range, 5.2-137.7 minutes) in the IT-knife group (P=0.209). Unlike the IT-knife group, which required additional devices in all cases, no additional devices were used in the H-knife group (P<0.001). En-bloc resection was performed for all lesions in both groups. The incidence of adverse events was not significantly different between groups (4.0% in the H-knife group vs. 8.3% in the IT-knife group; P=0.431). Conclusions: The newly developed hybrid device, the ClearCut^TM Knife H-type, had comparable efficacy to the conventional IT knife for gastric ESD.

• Journal of Biomedical Engineering Research
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• v.44 no.1
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• pp.25-32
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• 2023

Recognizing the size and location of prostate cancer is critical for prostate cancer diagnosis, treatment, and predicting prognosis. This paper proposes a model to classify the tumor region and normal tissue with cross-sectional visual images of prostatectomy tissue. We used specimen images of 44 prostate cancer patients who received prostatectomy at Gachon University Gil Hospital. A total of 289 prostate slice images consist of 200 slices including tumor region and 89 slices not including tumor region. Images were divided based on the presence or absence of tumor, and a total of 93 features from each slice image were extracted using Radiomics: 18 first order, 24 GLCM, 16 GLRLM, 16 GLSZM, 5 NGTDM, and 14 GLDM. We compared feature selection techniques such as LASSO, ANOVA, SFS, Ridge and RF, LR, SVM classifiers for the model's high performances. We evaluated the model's performance with AUC of the ROC curve. The results showed that the combination of feature selection techniques LASSO, Ridge, and classifier RF could be best with an AUC of 0.99±0.005.

• Journal of Chest Surgery
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• v.54 no.6
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• pp.543-546
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• 2021

A 55-year-old woman who had received an implantable left ventricular assist device 3 months earlier presented with dyspnea and a low-flow alarm of the device. Computed tomography and log-file analysis of the device system suggested inflow cannula obstruction. Since the patient had cardiogenic shock due to pump failure, venoarterial extracorporeal membrane oxygenation (ECMO) was initiated. With ECMO, surgical exchange of the pump was considered. However, the obstruction spontaneously resolved without surgical intervention. It turned out that an obstructive thrombus was washed out by rebooting the pump. Moreover, the thrombus was embolized in the patient's left subclavian artery. The patient underwent heart transplantation 4 months after the pump obstruction accident and continued to do well.

• Journal of Biomedical Engineering Research
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• v.41 no.2
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• pp.75-83
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• 2020

In large-scale hospitals, the department of biomedical engineering should always provide quick repair service for damaged medical devices to guarantee continuous patient treatment. However, in actual circumstances, there are so many time-consuming issues that delays device repair for weeks or even months; therefore, it is required to prepare alternative ways for quick repair service. In this study, we first mentioned about the regulation issues in Korea about the 3D printing-based medical device repair, and then introduced the results of our preliminary study that evaluated the feasibility of 3D printing-based medical device repair before real-field application. Results of the study demonstrated that, in all of the 23 cases, parts for repair that were manufactured by 3D-printing were successfully fixed and connected to the main body of the original device, and showed sufficient rigidity for protecting internal parts of the device. Considering the experimental results, medical device repair by applying 3D printing technology can be a promising alternative in cases when regular repair process is not available or takes too much time.

• Proceedings of the KAIS Fall Conference
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• 2011.05a
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• pp.385-388
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• 2011

The electromagnetic wave occurs primarily LED lighting equipment in the interior medical imaging information a lot of high-frequency equipment environment installation. It generated by lighting fixtures mach damage to patients as well as non or no operation. It can be reduced through noise attenuation and filter change. It associated with the capacitors and inductors can reduce by are used frequency efficiently, Attenuation circuit does not significantly affect the radiation medical equipment devices

• Health Policy and Management
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• v.31 no.4
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• pp.472-478
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• 2021

Background: Early identification of patients who are highly likely to develop severe illness among confirmed cases of coronavirus disease 19 (COVID-19) can be expected to lead to effective treatment. This study therefore aimed to determine whether the presence of nonalcoholic fatty liver disease (NAFLD) has an impact on the exacerbation of COVID-19 symptoms. Methods: The study used the Korean National Health Insurance claim data for treatment of COVID-19 patients in 2020. NAFLD includes nonalcoholic fatty liver (NAFL) and nonalcoholic steatohepatitis (NASH). The outcome variables used were hospitalization and the use of medical devices. Hospitalization was defined by a length of stay exceeding one day and the use of medical devices was defined as one or more uses of a ventilator or extracorporeal membrane oxygenation. Multivariable logistic regression analysis was performed to determine if there was a difference in the hospitalization and use of medical devices of COVID-19 patients depending on the presence of NAFLD. Results: The odds ratio of hospitalization was 1.059, indicating slightly higher odds of hospitalization for patients with NAFL or NASH compared to those without the conditions, but it was not statistically significant (0.969-1.156). On the other hand, the odds ratio of use of medical devices was high at 1.667 and was statistically significant (1.111-2.501). Conclusion: The study results found NAFLD to be a risk factor that can exacerbate symptoms in COVID-19 patients. Accordingly, it is necessary to identify NAFLD patients through preemptive screening and provide them with appropriate treatments.

• Korean Journal of Audiology
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• v.24 no.4
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• pp.161-166
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• 2020

Congenital aural atresia is an ear malformation evident at birth, involving various degrees of failed external ear canal development. A true external ear canal is desirable, as devices that replace the canal are inconvenient and expensive. Therefore, an optimal surgical technique is required. Here, we review useful preoperative and operative techniques. Surgical correction is often not the preferred treatment; the hearing outcome is no better than the outcomes afforded by bone-conduction devices, and surgery may be associated with recurrence or complications such as meatal stenosis. Preoperative evaluation and appropriate management are important. Several means of preventing meatal stenosis are discussed in this review.

• Journal of Audiology & Otology
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• v.24 no.4
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• pp.161-166
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• 2020

Congenital aural atresia is an ear malformation evident at birth, involving various degrees of failed external ear canal development. A true external ear canal is desirable, as devices that replace the canal are inconvenient and expensive. Therefore, an optimal surgical technique is required. Here, we review useful preoperative and operative techniques. Surgical correction is often not the preferred treatment; the hearing outcome is no better than the outcomes afforded by bone-conduction devices, and surgery may be associated with recurrence or complications such as meatal stenosis. Preoperative evaluation and appropriate management are important. Several means of preventing meatal stenosis are discussed in this review.

• Journal of information and communication convergence engineering
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• v.10 no.4
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• pp.337-342
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• 2012

The medical industries are integrated with information technology with mobile devices and wireless communication. The advent of mobile healthcare systems can benefit patients and hospitals, by not only providing better quality of patient care, but also by reducing administrative and medical costs for both patients and hospitals. Security issues present an interesting research topic in wireless and pervasive healthcare networks. As information technology is developed, many organizations such as government agencies, public institutions, and corporations have employed an information system to enhance the efficiency of their work processes. For the past few years, healthcare organizations throughout the world have been adopting health information systems (HIS) based on the wireless network infrastructure. As a part of the wireless network, a mobile agent has been employed at a large scale in hospitals due to its outstanding mobility. Several vulnerabilities and security requirements related to mobile devices should be considered in implementing mobile services in the hospital environment. Secure authentication and protocols with a mobile agent for applying ubiquitous sensor networks in a healthcare system environment is proposed and analyzed in this paper.