• Proceedings of the Korea Contents Association Conference
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• 2013.05a
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• pp.211-212
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• 2013

방사선 치료를 받는 모든 환자의 경우 먼저 모의 치료를 시행한 후에 동일한 자세로 방사선 치료를 실시한다. 이 때 무엇보다도 중요한 사항은 정확한 자세의 재현성이다. 직장암 환자의 방사선 치료를 시행하는 경우에도 모의 치료와 동일한 자세 유지가 요구되어진다. 하지만 호흡 및 환자의 여러 가지 요소에 의해 자세의 오차가 발생할 수 있다. 이에 본 논문은 직장암 환자의 방사선 치료를 시행하는 경우 오차가 발생할 수 있는 요소 중에 환자의 체지량 지수 차이에 의한 자세 재현성에 대해 알아보고 향후 자세 오차를 줄일 수 있는 방법을 모색하고자 한다.

• Proceedings of the Korean Society of Medical Physics Conference
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• 2003.09a
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• pp.59-59
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• 2003

목적 : 환자의 호흡에 의한 움직임 및 부정확한 환자 자세 setup 때문에 3 차원 전신 정위 방사선치료,3 차원 입체조형 방사선치료 IMRT와 같은 방사선 치료기술에서 병소에 대한 정확한 표적 위치측정은 매우 어려운 실정이다. 그러므로 본 연구는 방사선 치료시 환자의 움직임을 최대한 고정시켜 줄 수 있으며 환자 자세에 대한 setup 오차를 감소시키고 환자 전신에 산재한 병소의 위치를 좌표화할 수 있는 전신 정위 프레임 제작과 제작한 프레임에 대한 고정효과 및 재현성을 나타내는 환자 자세의 setup 오차를 평가하는데 있다. 재료 및 방법 : 자체 제작한 전신 정위 프레임 구조는 CT 영상 촬영 가능성에 중점을 두고 병소 표적의 좌표실현 및 환자체형에 따른 다양성 그리고 프레임에 대한 견고성 및 안정성 확인에 초점화하여 제작하였다. 이렇게 제작된 전신 정위 프레임에 대한 방사선 투과율 측정 실험과 CCTV 카메라와 DVR(Digital Video Recorder)를 이용해 환자 자세 변화에 대한 영상을 획득하여 matlab으로 구현한 오차분석용 프로그램으로 환자 외부자세에 대한 오차 비교 평가하고 CT 촬영에 의한 가상표적 위치측정 실험을 수행하였다. 또 한 고정벨트 추가 사용으로 인한 환자의 고정효과 정도를 살펴보았다. 결과 : 제작된 전신 정위 프레임에 대한 방사선 투과율은 마그네트론 10, 21 MeV의 에너지에서 95, 96% 의 투과율이 측정되었고 30 $^{\circ}$. 60 。각도의 경사로 빔이 전달될 때는 90.3, 94.4% 가 측정되었다. CCTV 카메라를 이용하여 흉부 및 복부의 움직임을 촬영한 영상을 Matlab프로그램으로 구현한 오차분석 프로그램을 적용한 결과, 환자 자세에 대한 오차의 평균값은 흉부의 lateral 방향에서는 3.63$\pm$1.4 mm, AP 방향에서는 2.1$\pm$0.82 mm이었다. 그리고 복부의 later의 방향에서는 7.0$\pm$2.1 mm, AP 방향에서는 6.5$\pm$2.2 mm 이었다. 또한 표적 위치측정을 위해서 환자의 피부에 임의의 가상표적을 부착하고 CT 촬영한 영상결과, 프레임으로 가상표 적에 대한 위치를 정확히 파악할 수 있었다. 결론 : 제작된 프레임을 적용하여 방사선투과율 측정실험, 환자 외부자세에 대한 오차 측정실험, 가상표적 위치측정 실험 등을 수행하였다. 환자 외부자세에 대한 오차 측정실험 경우, 더 많은 Volunteer를 적용하여 보다 정확한 오차 측정실험이 수행되어야 할 것이며 정확한 표적 위치 측정실험을 위해서 내부 마커를 삽입한 환자를 적용한 임상실험이 수행되어야 할 것이다. 또한 위치결정에서 획득한 좌표값의 정확성을 알아보기 위해서 팬톰을 이용한 방사선조사 실험이 추후에 실행되어져야 할 것이다. 그리고 제작된 프레임에 Rotating X선 시스템과 내부 장기의 움직임을 계량화하고 PTV에서의 최적 여유폭을 설정함으로써 정위 방사선수술 및 3 차원 업체 방사선치료에 대한 병소 위치측정과 환자의 자세에 대한 setup 오차측정 결정에 도움이 될 수 있을 것이라고 사료된다.

• The Journal of Korean Society for Radiation Therapy
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• v.27 no.2
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• pp.175-181
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• 2015

Purpose : To evaluate Contralateral Breast Doses with Supine and Prone Positions for tangential Irradiation techniques for left-sided breast Cancer Materials and Methods : We performed measurements for contralateral doses using Human Phantom at each other three plans (conventional technique, Field-in-Field, IMRT, with prescription of 50 Gy/25fx). For the measurement of contralateral doses we used Glass dosimeters on the 4 points of Human Phantom surface (0 mm, 10 mm, 30 mm, 50 mm). For the position check at every measurements, we had taken portal images using EPID and denoted the incident points on the human phantom for checking the constancy of incident points. Results : The contralateral doses in supine position showed a little higher doses than those in prone position. In the planning study, contralateral doses in the prone position increased mean doses of 1.2% to 1.8% at each positions while those in the supine positions showed mean dose decreases of 0.8% to 0.9%. The measurements using glass dosimeters resulted in dose increases (mean: 2.7%, maximum: 4% of the prescribed dose) in the prone position. In addition, the delivery techniques of Field-in-field and IMRT showed mean doses of 3% higher than conventional technique. Conclusion : We evaluated contralateral breast doses depending on different positions of supine and prone for tangential irradiations. For the phantom simulation of set-up variation effects on contralateral dose evaluation, although we used humanoid phantom for planning and measurements comparisons, it would be more or less worse set-up constancy in a real patient. Therefore, more careful selection of determination of patient set-up for the breast tangential irradiation, especially in the left-sided breast, should be considered for unwanted dose increases to left lung and heart. In conclusion, intensive patient monitoring and improved patient set-up verification efforts should be necessary for the application of prone position for tangential irradiation of left-sided breast cancer.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.6
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• pp.1231-1236
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• 2017

In this study, we developed a system that can change position to improve obstructive sleep apnea. Blocking of the breathing airway caused by obstruction of the apnea, lateral position is provided by the airway to improve the apnea. We used a pressure sensor (FSR402) in the form of an array to determine the position of patient. The air cylinder was controlled to raise and lower the bed. As a result of calculating the pressure difference between the supine position and the lateral position, it was $0.41{\pm}0.30$ and $1.09{\pm}0.73$. In other words, when the patient is lateral position, the difference between the sensor values on the right and left side is large. Therefore, it is confirmed that the system can maintain airway to breath for improvement of obstructive sleep.

• Science of Emotion and Sensibility
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• v.5 no.4
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• pp.67-75
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• 2002

The purpose of this study is to assess the ability of balance control in virtual moving surround stimulation using head mount display (HMD) device and force platform in patients with brain injury. Fifteen patients with stroke (mean age 54.47 yrs) and fifteen healthy normal persons participated. COP parameters were obtained total path distance, frequency of anterior-posterior and medial-lateral component by FFT analysis, weight-spectrum analysis in the two different conditions; (1) during comfortable standing with opened or closed eyes, (2) during virtual moving surround stimulation delivered using HMD with four different moving pattern. Moving patterns consisted of close-far, superior-inferior lilting (pitch) , right-left tilting (roll) and horizontal rotation (yaw) movement. In all parameters, the test-retest reliability was high. Also, the construct validity of virtual moving surround stimulation was excellent (p＜0.05). A posturographic balance assessment system equiped with virtual moving surround stimulation using HMD is considered clinically useful in evaluation of balance control in patients with brain injury.

• Journal of the Korean Society of Radiology
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• v.84 no.3
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• pp.627-637
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• 2023

Purpose To investigate the effect of patient positioning on tendinosis grade, visible range, and infraspinatus tendon (IST) thickness, and to determine the feasibility of internal rotation (IR) position to assess IST on ultrasound (US). Materials and Methods This study included 52 shoulders of 48 subjects who were evaluated for IST in three different positions: neutral position (N), IR, and position with the ipsilateral hand on the contralateral shoulder (HC). Two radiologists retrospectively graded IST tendinosis from grade 0 to grade 3 and the visible range from grade 1 to grade 4. The thickness of the IST was measured by another radiologist with a short-axis view. A generalized estimating equation was used for statistical analysis. Results The tendinosis grades were higher in the HC position than in the IR position, with a cumulative odds ratio of 2.087 (p = 0.004, 95% confidence interval [CI]: 1.268-3.433). The tendinosis grades in the HC position (p = 0.370) and IR position (p = 0.146) were not significantly different from those in the N position. The overall difference in IST thickness was significant (p < 0.001), but the visible range (p = 0.530) was not significantly different according to position. Conclusion Patient positioning significantly affected the grade of tendinosis and thickness but not the visible range of the IST. The IR position is a feasible position for assessing the IST on US.

• Science of Emotion and Sensibility
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• v.8 no.2
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• pp.95-101
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• 2005

This study is based on previous information regarding reduced cardiac vagal activity in patients with coronary artery disease(CAD), on reduced variance(SDNN : standard deviation of all normal RR intervals), low-frequency power(LF), and the complexity of heart rate variability(HRV) in patients with chronic heart failure(CHF), and on the normalized high-frequency power of HRV is the highest in the right lateral decubitus position among 3 recumbent postures in patients with CAD, However, nothing is known about the nonlinear dynamics of HRV for the 3 recumbent postures in patients with CAD. To investigate the linear and non-linear characteristics of HRV in patients with CAD, 29 patients as CAD group and 23 patients as control group were studied. Electrocardiogram(ECG) with lead II channel was measured on these patients for 3 recumbent postures in random order. The HRV from ECG was analyzed with linear method(for time and frequency domains) and nonlinear method. The lower the high-frequency power in normalized unit(nHF) in the supine or left lateral decubitous position, the higher the increase in nHF when the position was changed from supine or left lateral decubitous to right lateral decubitous. Among the 3 recumbent postures in patients with severe CAD, the right lateral decubitus position was observed to induce the highest vagal modulation, the lowest sympathetic modulation, and the highest complexity of human physiology system.

• Proceedings of the Korean Society of Computer Information Conference
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• 2021.07a
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• pp.503-506
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• 2021

본 연구에서는 적은 힘으로도 누워있는 환자의 자세를 바꾸어 줄 수 있는 침대 모형을 만들었다. 시중에서 판매되고 있는 변형 환자 침대는 침대의 변형을 수동으로 바꾸거나 침대에 연결되어 있는 구동기로 단순히 환자의 자세를 바꿀 수 있다. 본 연구에서 만들어진 침대는 침대를 다리 하단 / 다리 상단 / 상체 파트로 나누어 따로 또 병렬로 자세를 바꿀 기능을 구현하였을 뿐 아니라, 스마트폰 앱에 의한 제어 구동도 가능하고, 편안한 자세를 이루는 각 파트의 각도를 편리하게 기억시킬 수 있고, 버튼 한번 누름으로 기억된 형태로 구성이 가능하다. 또 누워있는 환자가 관절을 사용하지 않아 굳는 형태를 방지하기 위한 운동 기능이 추가되어 파트별로 운동을 시킬 수 있도록 하였다.

• Journal of the Korean Society of Radiology
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• v.8 no.5
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• pp.255-260
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• 2014

The acute lumbar pain patients who were unavoidable to take MRI examination were made to take altered lateral recumbent position. they were also not able to control their painfulness and to be in supine position. In this study, it is supposed to increase success rate of the MRI examination through taking the altered lateral recumbent position in using spine and body matrix coil. This altered position made relaxing lumber pain and fatigue for the patients who suffered from sever lumber pain. In these reasons, it decreases the motion artifacts through correcting uncomfortable posture. As a result, qualitative analysis for the image quality was estimated to have average points of supine position A group(lateral recumbent position) of normal candidates and B group(lateral recumbent position) of the abnormal candidates who have sever pain at 4.64, 3.44, and 3.40, respectively. In conclusion, while qualitative analysis in the examination with supine position of the normal patients had significantly high points, the qualitative analysis in the examination with lateral recumbent position of the normal patients and abnormal patients who had sever lumbar pain was almost same. In addition, it was judged that radiologists' imagery interpretation had no other problems in the image evaluation of B group who had acute lumbar pain of abnormal patients. Hereupon, if this technique becomes generalized for the patients who suffer from supine position in the examination, it is supposed to be useful in medical field.

• The Korean Journal of Nuclear Medicine Technology
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• v.16 no.1
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• pp.91-95
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• 2012

Purpose: In this study, we evaluated the ejection fraction (EF) according to the difference of patient position in Gated Blood Pool (GBP) scan. Material and Methods: The analysis was performed to 80 patients ($51.2{\pm}17.4$ years old) who examined GBP scan in Department of nuclear medicine, National Cancer Center from March 2011 to August 2011. We divided the patients into two groups; one group received conventional position (raise left arm up supine) and supine position (group 1) and the other group received conventional position and left arm back down supine position (group 2). To observe the change EF according to patient position difference, the image was reconstructed and analyzed by Xeleris (GE, USA). We measured body mass index (BMI) of patients. Result: In group 1, EF error less than 3% occurred at a rate of 72.5% (29 of the 40 patients). In group 2, EF error less than 3% occurred at a rate of 79% (32 of the 40 patients). The patient's BMI did not affect ejection fraction. Conclusion: The EF error of left arm back down supine position closer to conventional position than in supine position shows the results.