• Progress in Medical Physics
• /
• v.26 no.2
• /
• pp.112-117
• /
• 2015

In order to establish the quality control on patient safety following the guideline presented by American Association of Physicists in Medicine (AAPM) TG-100 committee, we aim to analyze the modes based on errors occurred during treatment of patients at the radiation oncology department at Yeungnam University Hospital and establish a quality control guideline for patient safety when patient-centered radiation treatment is conducted. We aim to analyze the errors that can occur during radiation treatment at the radiation department, and assess the frequency of error, the severity of error affecting patients, and probability of proceeding without noticing error, with scores. The places where errors can take place were divided into CT simulation treatment room, treatment planning room, and treatment room for the analysis. In CT simulation treatment room, an error from using the immobilization device showed the highest Risk Priority Number (RPN) value of 60, and an error from simulation treatment information input showed the lowest of 6. In treatment planning room, an error from selecting the radiation dose calculation model showed the highest RPN value of 168, and an error of patient treatment start date showed the lowest of 36. In treatment room, a Table Bar error showed the highest RPN value of 252, a weight change error showed 190, and a Pillow error showed the lowest of 24.

• Quality Improvement in Health Care
• /
• v.17 no.1
• /
• pp.89-105
• /
• 2011

Background : The purpose of study in to grasp the level of perception of hospital workers on the patient safety culture, consider the difference in perception of patients safety culture according to medical service and finally find out a way to establish patient safety culture in hospital. Methods : As for the data, the analysis on frequency, t-test, ANOVA and tukey test were carried out by using SPSS 12.0. Result : The results of comparison among the positive response ratios on the patients culture of hospital workers showed that the subjects had perceived the teamwork within units most positively(74.1%), and perceived most negatively on the non-punitive response to error(16.2%)and the staffing(26.2%). 68.6% of subjects answered that the medical error were mostly of always reported. when daytime working hours are longer, perception of patient safety culture ranked low. In general, departments for direct medical service than departments for indirect medical service assessed patient safety culture high. Conclusion : Organizational learning and teamwork within units, communication openness, active support of hospital management for patient safety, and cooperation across the units would be crucial to promote the overall perceptions of patients safety of hospital workers and the level of patients safety in the units and to improve the quality of the event reporting system.

• The Korean Journal of Nuclear Medicine Technology
• /
• v.21 no.1
• /
• pp.60-64
• /
• 2017

Purpose Westgard multi-rules application based on test quality improvement and commercialized international standard has been widely used in quality control. However, it is difficult to applicate the Westgard multi-rules in nuclear medicine in vitro tests due to the larger sample sizes and the simultaneous measurement of quality control material and patient sample. This study investigated the usefulness of Westgard multi-rules application in nuclear medicine in vitro tests. Materials and Methods A total of 282 systematic error multi-rules (22s, 101s) recorded in the samsung medical center computer system from January 2013 to June 2016 along with 117 cases of corrective measure record was analyzed. The Quality control implementation is recorded in Hospital information system were divided into 4 high-level areas including quality control material error, experimental procedural error, Kit lot number management error, and others. To prevent quality control material error, the existing method that each staff used their own method was changed. The staff who in charge of managing the quality control material was designated and daily consumption amount of every test was strictly controlled by one person. To prevent other errors, every test step was standardized so that the entire test procedures are identically implemented. Results The total quality control implementation was 117 cases; As a result, 62 quality control material errors were 62 cases, experimental process errors were 24 cases, Kit lot number control errors were 18 cases, and other errors were 13 cases. The quality control material error was corrected and could be used fresh materials within 2 days after thawing. The cases of systemic error were decreased to causes as quality control material error. The quality control materials were reduced above 10 vials to a monthly average. In addition, these errors of experimental processing and Kit lot number were improved by test standardization. Consequently, the cases of 101s and 22s in systematic error rules decreased at least 2 cases to a monthly average. Conclusion To confirm of systematic error through multi-rules application quickly, it is necessary to base on management of the QC material, target values and standard deviation. Moreover, in the event of a systematic error, it was found important to record measures based on test cause analysis. The experiment results are expected to contribute to internal quality control improvement and prompt and accurate result reporting through error recording and causal analysis based on Westgard multi-rules analysis.

• Journal of the korean veterinary medical association
• /
• v.37 no.8
• /
• pp.755-757
• /
• 2001

• Journal of Biomedical Engineering Research
• /
• v.36 no.5
• /
• pp.169-176
• /
• 2015

Implantable closed-loop epilepsy controllers require ideally both accurate epileptic seizure detection and low power consumption. On-chip oscillators can be used in implantable devices because they consume less power than other oscillators such as crystal oscillators. In this study, we investigated the tolerable error range of a lower power on-chip oscillator without losing the accuracy of seizure detection. We used 24 ictal and 14 interictal intracranial electroencephalographic segments recorded from epilepsy surgery patients. The performance variations with respect to oscillator frequency errors were estimated in terms of specificity, modified sensitivity, and detection timing difference of seizure onset using Generic Osorio Frei Algorithm. The frequency errors of on-chip oscillators were set at ${\pm}10%$ as the worst case. Our results showed that an oscillator error of ${\pm}10%$ affected both specificity and modified sensitivity by less than 3%. In addition, seizure onsets were detected with errors earlier or later than without errors and the average detection timing difference varied within less than 0.5 s range. The results suggest that on-chip oscillators could be useful for low-power implantable devices without error compensation circuitry requiring significant additional power. These findings could help the design of closed-loop systems with a seizure detector and automated stimulators for intractable epilepsy patients.

• Proceedings of the Korea Society of Information Technology Applications Conference
• /
• 2005.11a
• /
• pp.335-338
• /
• 2005

In this paper, we propose a downlink power control scheme to apply in the unequal error protection multi-code CDMA mobile medicine system. The mobile medicine system contains (i) blood pressure and body temperature measurement value, (ii) ECG medical signals measured by the electrocardiogram device, (iii) mobile patient's history, (iv) G.729 audio signal, MPEG-4 CCD sensor video signal, and JPEG2000 medical image. By the help of the multi-code CDMA spread spectrum communication system with downlink power control scheme and unequal error protection strategy, it is possible to transmit mobile medicine media and meet the quality of service. Numerical analysis and simulation results show that the system is a well transmission platform in mobile medicine.

• The Journal of Korean Society for Radiation Therapy
• /
• v.31 no.2
• /
• pp.65-74
• /
• 2019

Purpose: Recently, A Catcher was added to prevent sagging in Radixact^® X9. In this study, We quantitatively compared general couch of Tomo-HDA^® with catcher couch of Radixact^® X9 using the human phantom and evaluated usefulness of catcher. Materials and methods: We used rando phantom for phantom study and set the each iso-center of head and neck region and Pelvis region for region parameter. Furthermore, We used hand made low melting point alloys for weight parameter. MVCT(Mega Voltage Computed Tomography) images were acquired for vertical error and rotation(pitch) error measurement increasing weight(A: 15kg, A+B: 30kg, A+B+C: 45kg). We selected 120 patients who has been treated using Tomotherpy machine for patient study. 60 patients has been treated in Tomo-HDA^® and the other 60 patients treated in Radixact^® X9. In the patient study methods, vertical error and rotation(pitch) error was measured for mean value calculation using MVCT images acquired on first day of radiation therapy. Result: Result of phantom study, Vertical error and rotation(pitch) error was increased proportionally increased as the weight increases in general couch of Tomo-HDA^®. each maximum value was 7.52mm, 0.38° in head and neck region and 11.94mm, 0.92° in pelvis region. However, We could confirm that there was stable error range(0.02~0.1mm, 0~0.04°) in Catcher couch of Radixact^®. Result of patient study, The head and neck region was measured 4.79mm 0.33° lower, and the pelvis region was measured 7.66mm, 0.22° lower in Catcher couch of Radixact^® X9. Conclusion: In this study, Vertical error and rotation(pitch) error was proportionally increased as the weight increases in general couch of Tomo-HDA^®. Especially, The pelvis region error was more increased than the head and neck region error. However, Vertical error and rotation(pitch) error was regularly generated regardless of weight or regions in Catcher^TM couch of Radixact^® X9 that this study's purpose. In conclusion, Catcher^TM couch of Radixact^® X9 can minimize mechanical error that couch sagging. Furthermore, The pelvis region is more efficiency than head and neck region. In radiation therapy using Tomotherapy machine, it is regarded that may contribute to minimizing unadjusted pitch error due to characters of Tomotherapy.

• English Language & Literature Teaching
• /
• v.13 no.1
• /
• pp.47-66
• /
• 2007

Error analysis plays an important role because understanding the types of errors can give a better opportunity for both teachers and learners to recognize the nature of errors and ways of preventing them. This study looks into errors in the medical research abstracts written by 26 Koreans and also examines hedging expressions since hedging can be a necessary tactic in which the validity and objectivity of their claims is conveyed. The hedging expressions of these research abstracts are to be compared with those of Hyland (1996)'s study done on ENL academic writers of cell and molecular biology. The results of the study reveal that wrong word choice was the most commonly occurred errors, followed by prepositions, articles, adding and missing words. Many of these errors, except articles, seemed to derive from the native language interference. There were also run-on sentences, subject & verb agreement, tense, word order and minor errors. As for hedging, ESL medical writers seemed to use very limited hedging expressions and inappropriately strong modals. It is recommended to take variations of hedges using epistemic adverbials and adjectives to present their claims in a more valid and polite way. Limited verb choice was also noted. As for preventing or minimizing similar future errors, collocation practices in ESP focused on commonly used medical related words and expressions can be effective.

• Radiation Oncology Journal
• /
• v.29 no.3
• /
• pp.206-213
• /
• 2011

Purpose: Intensity modulated radiation therapy (IMRT) is a high precision therapy technique that can achieve a conformal dose distribution on a given target. However, organ motion induced by respiration can result in significant dosimetric error. Therefore, this study explores the dosimetric error that result from various patterns of respiration. Materials and Methods: Experiments were designed to deliver a treatment plan made for a real patient to an in-house developed motion phantom. The motion pattern; the amplitude and period as well as inhale-exhale period, could be controlled by in-house developed software. Dose distribution was measured using EDR2 film and analysis was performed by RIT113 software. Three respiratory patterns were generated for the purpose of this study; first the 'even inhale-exhale pattern', second the slightly long exhale pattern (0.35 seconds longer than inhale period) named 'general signal pattern', and third a 'long exhale pattern' (0.7 seconds longer than inhale period). One dimensional dose profile comparisons and gamma index analysis on 2 dimensions were performed. Results: In one-dimensional dose profile comparisons, 5% in the target and 30% dose difference at the boundary were observed in the long exhale pattern. The center of high dose region in the profile was shifted 1 mm to inhale (caudal) direction for the 'even inhale-exhale pattern', 2 mm and 5 mm shifts to exhale (cranial) direction were observed for 'slightly long exhale pattern' and 'long exhale pattern', respectively. The areas of gamma index >1 were 11.88 %, 15.11%, and 24.33% for 'even inhale-exhale pattern', 'general pattern', and 'long exhale pattern', respectively. The long exhale pattern showed largest errors. Conclusion: To reduce the dosimetric error due to respiratory motions, controlling patient's breathing to be closer to even inhaleexhale period is helpful with minimizing the motion amplitude.

• The Journal of Korean Society for Radiation Therapy
• /
• v.16 no.2
• /
• pp.81-89
• /
• 2004

Introduction : The setup error due to the patient and the staff from radiation treatment as the reason which is important the treatment record could be decided is a possibility of effect. The SET-UP ERROR of the patient analyzes the effect of dose distribution and DVH from radiation treatment of the patient. Material & Methode : This test uses human phantom and when C-T scan doing, It rotated the Left direction of the human phantom and it made SET-UP ERROR , Standard plan and 3mm, 5mm, 7mm, 10mm, 15mm, 20mm with to distinguish, it made the C-T scan error. With the result, The SET-UP ERROR got each C-T image Using RTP equipment It used the plan which is used generally from clinical - Box plan, 3Dimension plan( identical angle 5beam plan) Also, ( CTV+1cm margin, CTV+0.5cm margin, CTV+0.3,cm margin = PTV) it distinguished the standard plan and each set-up error plan and The plan used a dose distribution and the DVH and it analyzed Result : The Box4 the plan and 3Dimension plan which it bites it got similar an dose distribution and DVH in 3mm, 5mm From rotation error and Rectilinear movement( $0\%{\sim}2\%$ ). Rotation error and rectilinear error 7mm, 10mm, 15mm, 20mm appeared effect it will go mad to a enough change in treatment ( $2\%{\sim}^11\%$ ) Conclusion : The diminishes the effect of the SET-UP ERROR must reduce move with tension of the patient Also, we are important accessory development and the supply that it reducing of reproducibility and the move