Coronary Artery Stent Evaluation Using a Vascular Model at 64-Detector Row CT: Comparison between Prospective and Retrospective ECG-Gated Axial Scans

Shigeru Suzuki,Shigeru Furui,Tatsuro Kaminaga,Akiyoshi Miyazawa,Yasunari Ueno,Kumiko Konno,Sadatoshi Kuwahara,Dhruv Mehta 대한영상의학회 2009 Korean Journal of Radiology Vol.10 No.3

Objective: We wanted to evaluate the performance of prospective electrocardiogram (ECG)-gated axial scans for assessing coronary stents as compared with retrospective ECG-gated helical scans. Materials and Methods: As for a vascular model of the coronary artery, a tube of approximately 2.5-mm inner diameter was adopted and as for stents, three (Bx-Velocity, Express2, and Micro Driver) different kinds of stents were inserted into the tube. Both patent and stenotic models of coronary artery were made by instillating different attenuation (396 vs. 79 Hounsfield unit [HU]) of contrast medium within the tube in tube model. The models were scanned with two types of scan methods with a simulated ECG of 60 beats per minute and using display field of views (FOVs) of 9 and 18 cm. We evaluated the in-stent stenosis visually, and we measured the attenuation values and the diameter of the patent stent lumen. Results: The visualization of the stent lumen of the vascular models was improved with using the prospective ECG-gated axial scans and a 9-cm FOV. The inner diameters of the vascular models were underestimated with mean measurement errors of -1.10 to -1.36 mm. The measurement errors were smaller with using the prospective ECG-gated axial scans (Bx-Velocity and Express2, p < 0.0001; Micro Driver, p = 0.0004) and a 9-cm FOV (all stents: p < 0.0001), as compared with the other conditions, respectively. The luminal attenuation value was overestimated in each condition. For the luminal attenuation measurement, the use of prospective ECG-gated axial scans provided less measurement error compared with the retrospective ECG-gated helical scans (all stents: p < 0.0001), and the use of a 9-cm FOV tended to decrease the measurement error. Conclusion: The visualization of coronary stents is improved by the use of prospective ECG-gated axial scans and using a small FOV with reduced blooming artifacts and increased spatial resolution. Objective: We wanted to evaluate the performance of prospective electrocardiogram (ECG)-gated axial scans for assessing coronary stents as compared with retrospective ECG-gated helical scans. Materials and Methods: As for a vascular model of the coronary artery, a tube of approximately 2.5-mm inner diameter was adopted and as for stents, three (Bx-Velocity, Express2, and Micro Driver) different kinds of stents were inserted into the tube. Both patent and stenotic models of coronary artery were made by instillating different attenuation (396 vs. 79 Hounsfield unit [HU]) of contrast medium within the tube in tube model. The models were scanned with two types of scan methods with a simulated ECG of 60 beats per minute and using display field of views (FOVs) of 9 and 18 cm. We evaluated the in-stent stenosis visually, and we measured the attenuation values and the diameter of the patent stent lumen. Results: The visualization of the stent lumen of the vascular models was improved with using the prospective ECG-gated axial scans and a 9-cm FOV. The inner diameters of the vascular models were underestimated with mean measurement errors of -1.10 to -1.36 mm. The measurement errors were smaller with using the prospective ECG-gated axial scans (Bx-Velocity and Express2, p < 0.0001; Micro Driver, p = 0.0004) and a 9-cm FOV (all stents: p < 0.0001), as compared with the other conditions, respectively. The luminal attenuation value was overestimated in each condition. For the luminal attenuation measurement, the use of prospective ECG-gated axial scans provided less measurement error compared with the retrospective ECG-gated helical scans (all stents: p < 0.0001), and the use of a 9-cm FOV tended to decrease the measurement error. Conclusion: The visualization of coronary stents is improved by the use of prospective ECG-gated axial scans and using a small FOV with reduced blooming artifacts and increased spatial resolution.

Characteristic Evolution of Residual Stress in Shape Memory Fe-Mn-Si-Cr Alloys

Suzuki, Shigeru,Kwon, Eui Pyo,Tanaka, Shunichiro Trans Tech Publications, Ltd. 2014 Materials science forum Vol.768 No.-

<P>Since the matrix phase is transformed to martensitic phase in shape memory alloys (SMAs) during plastic deformation, complicated residual stresses may arise during deformation, and they may affect the shape recovery ability of the alloys. Thus, it is important to be able to characterize the residual stresses formed in SMAs during plastic deformation and annealing. In this study, X-ray diffraction was used to characterize the residual stress formed in a Fe-Mn-Si-Cr SMA, which was deformed in the tensile direction and subsequently annealed. The results showed that the compressive stress persisted in the tensile direction of the face-centered cubic (fcc) matrix upon tensile deformation and unloading. Compressive stress is believed to result from the hexagonal close-packed (hcp) phase formed during stress-induced martensitic transformation. After the deformed samples were annealed to recover their shapes, the residual stress was considerably reduced. This is believed to be due to the decrease in the formation of the hcp phase or to the recovery of their shapes during annealing. Our results indicated that residual stress in the fcc matrix phase is associated with the shape recovery characteristics of the alloys after martensitic and reverse martensitic transformations.</P>

거짓쌀도둑거저리 집합페로몬의 생합성

김준헌,Shigeru Matsuyama,Takahisa Suzuki 한국응용곤충학회 2009 한국응용곤충학회 학술대회논문집 Vol.2009 No.05

딱정벌레목의 곤충의 페로몬은 나비목의 페로몬과는 달리 매우 다양한 구 조를 보이고 있으며, 그 생합성 과정에서도 이러한 다양성을 보이고 있다. 거 저리과(Coleoptera: Tenebrionidae)의 페로몬 또한 다양성을 보여, Tribolium castenum, T. confusum, T. freemani의 4,8-dimethyldecanal, Tenebrio molitor의 4-methyl-1-nonanol, (Z)-3-dodecenyl aceatate, Gnatocerus cornutus의 (+)-acoradiene, a-cedrene-14-al이 페로몬으로 이용되며, Te. molitor의 페로몬은 지방산 경로를 통해, G. cornutus 는 테르펜 경로를 통해 생합성 되는 다양함을 보인다. 한편, Tribolium spp.의 페로몬은 4,8-DMD의 구조로부터 지방산 경로 또는 mevalonate를 경유하는 테 르펜 생합성 경로로부터 생합성 될 수 있음을 보인다. 이에 Tribolium spp.의 집합 페로몬 4,8-DMD의 생합성 과정을, T. castaneum을 대상으로 대사 저해제 를 통한 생합성 경로의 유추, 동위 원소 표식된 생합성 구성 단위(building block)에 의한 생합성 경로 확인 및 합성된 동위원소 표식 예상 전구 물질를 통한 생합성 대사과정의 확인을 통해 구명하였다. 본 소모임에서는 페로몬 생 합성 과정을 구명하기 위해 행하여진 위 실험들에 관하여 소개하고자 한다

Current Status of NeLS Project-A Study of Global Multimedia Mobile Satellite Communications

Suzuki, Ryutaro,Nishiyama, Iwao,Motoyoshi, Shigeru,Yasuda, Yasuhiko 통신위성우주산업연구회 2001 Joint Conference on Satellite Communications Vol.2001 No.-

NeLS Research Center was formed in the end of 1997, and started the key technology developments of the low earth orbit constellation system for global multimedia mobile satellite communications service. For the NeLS constellation, 120 satellites with 1200 km of satellite altitude, was selected. For the satellite antenna developments, the digital beam forming technology was employed. In order to reduce the SSPA power consumption and to keep good linearity, novel pre-distortion type and distortion feedback type linearizer were developed. For the optical ISL system, de optical modem and optical tracking mechanism were developed. The optical DPSK/differential detection modem was evaluated. For the optical antenna mechanism, Coude type, the elbow type and the active universal joint type of optical antenna mechanism were developed. For the satellite network study, the satellite ATM network simulator was developed.

Coherent Hybrid DS-FFH CDMA with Adaptive Interference Cancelling for Cellular Communications

Shigeru Tomisato,Kazuhiko Fukawa,Hhrishi Suzuki 대한전자공학회 1993 JTC-CSCC : Joint Technical Conference on Circuits Vol.- No.-

Discrete-Time Learning Control for Robotic Manipulators

TATSUYA SUZUKI,MASANORI YASUE,SHIGERU OKUMA,YOSHIKI UCHIKAWA 제어로봇시스템학회 1989 제어로봇시스템학회 국내학술대회 논문집 Vol.1989 No.10

Discrete-Time Learning Control for Robotic Manipulators

Tatsuya Suzuki,Masanori Yasue,Shigeru Okuma,Yoshiki Uchikawa 대한전자공학회 1989 대한전자공학회 학술대회 Vol.1989 No.01

Aggregation Pheromone Biosynthesis in the Red Flour Beetle, Tribolium castaneum (Coleoptera: Tenebrionidae)

Junheon Kim,Shigeru Matsuyama,Takahisa Suzuki 한국응용곤충학회 2005 한국응용곤충학회 학술대회논문집 Vol.2005 No.05

Trajectory Control of Direct Drive Robot with Two-Degree-of-Freedom Compensator

Jeong-Ho SHIN,Tatsuya SUZUKI,Shigeru OKUMA 전력전자학회 1995 ICPE(ISPE)논문집 Vol.1995 No.10

Recently, a disturbance observer based controller has been widely used in the industrial world because of its simplicity. However, this method depends on the intuitive approach in determining the disturbance estimation filter, therefore, more systematic approach is desired. In this paper, we make a bridge between the gen­eralized compensator and the disturbance observer based controller by clarifying the internal structure of the gen­eralized two-degree-of-freedom compensator. We apply the proposed algorithm to a trajectory control of a three-degree-of-freedom direct drive robot, and show some ex­perimental results to verify the effectiveness of the pro­posed algorithm.

Application of Tinel’s test combed with clinical neurosensory test distinguishes spontaneous healing of lingual nerve neuropathy after mandibular third molar extraction

Shigeyuki Fujita,Itaru Tojyo,Shigeru Suzuki,Fumihiro Tajima 대한악안면성형재건외과학회 2023 Maxillofacial Plastic Reconstructive Surgery Vol.45 No.-

Background Extraction of the mandibular third molar, the most frequent and important surgical procedure in the clinical practice of oral surgery, is associated with the risk of injury of the lingual nerve. Neuropathy of the lingual nerve poses diagnostic challenges regarding the transient or permanent nature of the injury. No consensus or criteria have been established regarding the diagnosis of lingual nerve neuropathy. We applied both Tinel’s test and clinical neurosensory testing together, which can be easily used at the bedside in the early stages of injury. Therefore, we propose a new method to differentiate between lesions with the ability to heal spontaneously and those that cannot heal without surgery. Results Thirty-three patients (29 women, 4 men; mean age, 35.5 years) were included in this study. For all patients, the median interval between nerve injury and initial examination was 1.6 months and that between nerve injury and the second examination before determining the need for surgical management was 4.5 months. The patients were assigned to either group A or B. The spontaneous healing group (group A, n = 10) revealed a tendency for recovery within 6 months after tooth extraction. In this group, although there were individual differences in the degree of recovery, a remarkable tendency for recovery was observed based on clinical neurosensory testing in all cases. None of the patients were diagnosed with allodynia. In seven cases, the Tinel test result was negative at the first inspection, and in three cases, the result changed to negative at the second inspection. Conversely, in group B(n = 23), no recovery trend was observed with regard to clinical neurosensory testing, and nine patients had allodynia. Further, the Tinel test result was positive for all patients in both examinations. Conclusions Our findings indicate that in case of transient lingual nerve paralysis, clinical neurosensory testing findings deteriorate immediately after tooth extraction and gradually recover, while Tinel’s test shows a negative result. Using Tinel’s test and clinical neurosensory testing together enabled early and easy identification of the severity of the lingual nerve disorder and of lesions that would heal spontaneously without surgical management.