Single-channel stereoscopic imaging system using rotating deflector

Dept. of Biomedical Engineering/석사In a conventional dual-channel stereoscopic imaging system (SIS), two cameras are often used to take images at different visual orientations, creating a three-dimensional (3D) image. Because two cameras are used, visual fatigue may be caused by differences between the cameras involving temporal synchronization, geometrical calibration, and color balance. Furthermore, owing to its mechanical composition, the imaging system is generally bulky.To eliminate the possible limitations of current conventional dual-camera SISs, research was conducted to develop a 3D SIS using a single camera. Its purpose is to create image disparity (ID), a key factor in producing stereoscopic images. Using a transparent rotating deflector (TRD), ID was mimicked assuming that light refraction through the TRD would create the necessary ID.First, the system’s efficacy was tested using a thorough simulation and experiment based on Snell’s law. Light propagation through the TRD was modeled using ZEMAX. The ID was calculated for various TRD refractive indices and thicknesses. On the basis of the simulation and calculation, a TRD-based SIS (TRD-SIS) was developed using manual rotation of the TRD. Second, a real-time TRD-SIS was set up to allow real-time stereoscopic imaging and display. A complementary metal–oxide–semiconductor (CMOS) camera was used along with a stepping motor controlled by a microcontroller unit. The acquiredimages were visualized in 3D using an active 3D method. Finally, the system was evaluated in terms of two factors: (1) temperature generation and (2) the image characteristics. The temperature changes in the optical components were measured at the motor surface and motor driver. The image characteristics were evaluated by calculating the coefficient of variation of acquired images of a white reflectance target. In addition, a method of controlling heat generation using a heat sink and motor fan was devised.ope

Ultrasound-guided myofascial trigger point injection into brachialis muscle for rotator cuff disease patients with upper arm pain: a pilot study

OBJECTIVE: To assess the efficacy of trigger point injection into brachialis muscle for rotator cuff disease patients with upper arm pain. METHODS: A prospective, randomized, and single-blinded clinical pilot trial was performed at university rehabilitation hospital. Twenty-one patients clinically diagnosed with rotator cuff disease suspected of having brachialis myofascial pain syndrome (MPS) were randomly allocated into two groups. Effect of ultrasound (US)-guided trigger point injection (n=11) and oral non-steroidal anti-inflammatory drug (NSAID) (n=10) was compared by visual analog scale (VAS). RESULTS: US-guided trigger point injection of brachialis muscle resulted in excellent outcome compared to the oral NSAID group. Mean VAS scores decreased significantly after 2 weeks of treatment compared to the baseline in both groups (7.3 vs. 4.5 in the injection group and 7.4 vs. 5.9 in the oral group). The decrease of the VAS score caused by injection (ДVAS=-2.8) was significantly larger than caused by oral NSAID (ДVAS=-1.5) (p<0.05). CONCLUSION: In patients with rotator cuff disease, US-guided trigger point injection of the brachialis muscle is safe and effective for both diagnosis and treatment when the cause of pain is suspected to be originated from the muscle.ope

Relationship between Respiratory Muscle Strength and Cardiac Function in Duchenne Muscular Dystrophy

OBJECTIVE: To investigate the relationship between respiratory muscle strength and cardiac function in patients with Duchenne muscular dystrophy (DMD). METHOD: This study included 37 patients with DMD. Cardiac function of patients was evaluated by thoracic echocardiography, which recorded left ventricular ejection fraction (LVEF). Maximal expiratory pressure (MEP) and maximal inspiratory pressure (MIP) representing respiratory muscle strength and blood sampling for brain natriuretic peptide (BNP) were performed. RESULTS: LVEF did not show significant correlation with MIP, MEP or age. However, LVEF was negatively correlated with BNP level. CONCLUSION: Cardiac dysfunction of patients with DMD didn't correlate with age or respiratory muscle strength. Therefore, investigation of cardiac function itself is needed for patients with DMD irrespective of respiratory compromisesope

Early detection of cutaneous radiation injury using optical imaging techniques

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Bladder-filling sensation in patients with complete spinal cord injury

의학과/석사[한글] 척수손상으로 인한 신경인성 방광의 관리에 있어 적절한 감각의 전달이 이루어지지 않는 완전 척수손상 환자에서는 부적절한 도뇨 시기로 인한 여러 부작용을 초래할 수 있다. 기존의 연구에서 완전 척수손상 환자 중 일부에서 배뇨 감각이 보존되어 있다고 보고하고 있으며 이를 임상적으로 이용한다면 부적절한 도뇨 시기의 단점을 보완할 수 있을 것이라는 주장이 있다. 하지만 배뇨 감각이 보존된 완전 척수손상 환자의 임상과 요류동태검사상 특성에 대한 연구가 부족하며, 완전 척수손상 환자의 배뇨감각이 보존된 경우 모든 경우에서 이를 이용한 도뇨 시기의 결정이 적합한 지에 대한 연구 또한 부족하다. 이에 본 연구에서는 요류동태검사를 시행한 제10 흉수 이상의 완전 척수손상 환자 203명을 배뇨 감각이 보존된 군과 그렇지 않은 군으로 분류하고, 각 군의 임상과 요류동태검사상의 특성을 비교하여, 보존된 배뇨 감각을 이용한 도뇨 시기의 결정이 바람직한 지를 알아보고자 하였다. 본 연구 결과 총 203례의 완전 척수손상 환자 중 73례(36.0%)에서 배뇨감각이 보존되어 있었다. 배뇨 감각이 보존된 73례 중 초기 배뇨감의 배뇨근압이 40 cmH2O 미만이 경우가 84.9%에 해당하는 62례였으며, 40 cmH2O 이상인 경우가 15.1%에 해당하는 11례였다. 배뇨 감각이 보존된 군에서 배뇨 감각이 보존되지 않은 군에 비해 유의하게 순응도가 낮았으며 유병기간이 길었다(p<0.05). 초기 배뇨감의 배뇨근압이 높은 군과 낮은 군에서 유의한 임상적 차이는 없었다. 본 연구를 통해 완전 척수손상 환자 중 36.0%의 경우에서 배뇨 감각이 보존되어 있음을 알 수 있었으며, 이러한 배뇨 감각의 보존은 순응도가 낮은 결과일 가능성이 높아 배뇨 감각이 보존된 모든 완전 척수손상 환자에서 배뇨 감각을 이용하여 도뇨 시기를 결정하는 것은 적절하지 않은 방법임을 알 수 있었다. [영문]In spinal cord injury(SCI) patients, physiological changes in urinary excretion may lead to unnecessary emptying attempt or to bladder overdistension because voiding methods are performed in a time-dependent manner. Previous studies reported that the presence of bladder-filling sensation in many of the complete SCI patients revealed the potential for sensation-dependent bladder emptying. However there were few studies for the clinical and urodynamic characteristics of the complete SCI patients with the preservation of bladder-filling sensation. The aims of this study were to classify complete SCI patients based on the preservation of bladder-filling sensation and to compare the clinical and urodynamic characters between the preservation of bladder-filling sensation group. The main goal was to investigate the potential for sensation-dependent bladder emptying in complete SCI patients with the preservation of bladder-filling sensation. This study was performed retrospectively on 203 complete SCI patients with lesions above T11 who were referred to the urodynamics laboratory. Patients were classified according to the preservation of bladder-filling sensation during conventional urodynamic study. Patients in the sensory preservation group were also classified according to the detrusor pressure of 40 cmH2O at bladder-filling sensation. The clinical and urodynamic characteristics of each groups were analyzed. There were 73 patients(36.0%) with the preservation of bladder-filling sensation. There were 62 patients who were showed the acceptable detrusor pressure at bladder-filling sensation. There were significantly lower compliance of bladder and longer duration from onset to examination in the sensory preservation group(p<0.05). There were no significant clinical difference between high and acceptable detrusor pressure at bladder-filling sensation groups. In conclusion the presence of bladder-filling sensation in 36% complete SCI patients observed. However it was unreasonable that the sensation-dependent bladder emptying was possible for all complete SCI patients with the preservation of bladder-filling sensation.ope

Assessment of post-stroke extrapersonal neglect using a three-dimensional immersive virtual street crossing program

OBJECTIVE: To investigate the potential of our newly developed three-dimensional immersive virtual reality (VR) program modeled on a real street crossing as an assessment tool for extrapersonal neglect in stroke patients. METHODS: Thirty-two patients with right-hemispheric stroke (neglect group, 16; non-neglect group, 16) were enrolled. The deviation angle, reaction time, left-to-right reaction time ratio, visual and auditory cue rates, and failure rate were evaluated during missions to keep a virtual avatar safe from a traffic accident in the VR program. The line bisection test and letter cancellation test were also evaluated. RESULTS: The deviation angle, left-to-right reaction time ratio, left visual and auditory cue rates and left failure rate in the VR program showed significant differences between the two groups (P < 0.05). Depending on the direction of approach of the virtual car, the left parameters were significantly higher than the right parameters in the neglect group (P < 0.05). In the neglect group, the line bisection test correlated significantly with the deviation angle (P < 0.05). None of the other virtual reality parameters significantly correlated with the paper and pencil tests. CONCLUSION: Post-stroke neglect in the extrapersonal space can be easily and safely detected and measured using our three-dimensional immersive virtual street crossing program.ope

The determination of sensation-dependent bladder emptying time in patients with complete spinal cord injury above T11

STUDY DESIGN: Retrospective investigation using urodynamic studies and medical records. OBJECTIVE: To evaluate the safety of sensation-dependent bladder emptying in complete spinal cord injury (SCI) patients, based on the preservation of the desire to void. SETTING: Spinal Cord Injury Unit, Yonsei Rehabilitation Hospital, Seoul, Korea. METHODS: This study was performed retrospectively on 79 complete SCI patients with lesions above T11, who had preserved the desire to void during conventional urodynamic studies. Patients were classified according to detrusor compliance and maximal bladder capacity. The clinical and urodynamic characteristics of each group were analyzed. RESULTS: Forty-five (57.0%) patients were classified as group A and 34 (43.0%) patients were classified as group B. There were no significant differences in clinical features, such as voiding methods and the presence of autonomic dysreflexia between the two groups. Compared with group B, there were significantly more areflexic neurogenic bladder cases in group A (P<0.05). There were significantly higher maximal detrusor pressures in group B (P<0.05). There were significantly more cases with the preservation of the strong desire to void in group B (P<0.05). CONCLUSION: Not all patients with discomplete SCIs accepted the use of sensation-dependent bladder emptying. The safe use of sensation-dependent bladder emptying will be determined based on the results of urodynamic studies.ope

Characterization of early-stage ionizing radiation induced skin injury in a mouse model by two-photon microscopy and optical coherence tomography

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Visualization of prostatic nerves by polarization-sensitive optical coherence tomography

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Moxifloxacin: Clinically compatilble contrast agent for multiphoton imaging

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