Development of smart transducer with embedded sensor for automatic process control of ultrasonic wire bonding

Or, Siu Wing,Chan, Helen Lai Wa,Liu, Peter Chou Kee Techno-Press 2005 Smart Structures and Systems, An International Jou Vol.1 No.1

A ring-shaped lead zirconate titanate (PZT) piezoceramic sensor has been integrated with the Langevin-type piezoceramic driver of an ultrasonic wire-bonding transducer to form a smart transducer for in-situ measurement of three essential bonding parameters: namely, impact force, ultrasonic amplitude and bond time. This sensor has an inner diameter, an outer diameter and a thickness of 12.7 mm, 5.1 mm and 0.6 mm, respectively. It has a specifically designed electrode pattern on the two major surfaces perpendicular to its thickness along which polarization is induced. The process-test results have indicated that the sensor not only is sensitive to excessive impact forces exerted on the devices to be bonded but also can track changes in the ultrasonic amplitude proficiently during bonding. Good correlation between the sensor outputs and the bond quality has been established. This smart transducer has good potential to be used in automatic process-control systems for ultrasonic wire bonding.

Modifi ed Radiology-Guided Percutaneous Gastrostomy (MRPG) for Patients with Complete Obstruction of the Upper Digestive Tract and Who are without Endoscopic or Nasogastric Access

Siu-Cheung Chan,Winnie Chiu-Wing Chu,Kar-Wai Liu,Chun-Ta Liao,Tsung-Shih Lee,Shu-Hang Ng 대한영상의학회 2011 Korean Journal of Radiology Vol.12 No.2

Objective: We wanted to report on our experience with modified radiology-guided percutaneous gastrostomy (MRPG) without endoscopic or nasogastric access for treating patients with complete obstruction of the upper digestive tract. Materials and Methods: Fourteen oncology patients (13 had hypopharyngeal cancer and 1 had upper esophageal cancer) with complete obstruction of the upper digestive tract were recruited. Conventional percutaneous endoscopic gastrostomy (PEG) and radiologic (fl uoroscopy-guided) percutaneous gastrostomy (RPG) were not feasible in all the patients. An MRPG technique (with a combination of ultrasound, an air enema and fl uoroscopic guidance) was performed in these patients. Results: We achieved successfully percutaneous gastrostomy using the modifi ed technique in all patients without any major or minor complications after the procedure. Conclusion: A modifi ed radiology-guided percutaneous gastrostomy technique can be safely performed in patients who failed to receive conventional PEG or RPG due to the absence of nasogastric access in the completely obstructed upper digestive tract. Objective: We wanted to report on our experience with modified radiology-guided percutaneous gastrostomy (MRPG) without endoscopic or nasogastric access for treating patients with complete obstruction of the upper digestive tract. Materials and Methods: Fourteen oncology patients (13 had hypopharyngeal cancer and 1 had upper esophageal cancer) with complete obstruction of the upper digestive tract were recruited. Conventional percutaneous endoscopic gastrostomy (PEG) and radiologic (fl uoroscopy-guided) percutaneous gastrostomy (RPG) were not feasible in all the patients. An MRPG technique (with a combination of ultrasound, an air enema and fl uoroscopic guidance) was performed in these patients. Results: We achieved successfully percutaneous gastrostomy using the modifi ed technique in all patients without any major or minor complications after the procedure. Conclusion: A modifi ed radiology-guided percutaneous gastrostomy technique can be safely performed in patients who failed to receive conventional PEG or RPG due to the absence of nasogastric access in the completely obstructed upper digestive tract.

Quantitative Anatomy of C7 Vertebra in Southern Chinese for Insertion of Lateral Mass Screws and Pedicle Screws

Michael Siu Hei Tse,Chi Hin Chan,Kam Kwong Wong,Wing Cheung Wong 대한척추외과학회 2016 Asian Spine Journal Vol.10 No.4

Study Design: Retrospective study. Purpose: To analyze the quantitative anatomy of C7 vertebra for insertion of lateral mass screws and pedicle screws in Southern Chinese patients. Overview of Literature: C7 lateral mass is smaller when compared to other subaxial cervical levels, which limits the length of lateral mass screws that can be used. Some studies have suggested pedicle screws for better fixation. But, this option is limited by the narrow pedicle width. Methods: We have obtained computed tomography (CT) cervical spine data in 0.625 mm slices from our radiology department. The patients were adults. CTs were from May to August, 2015. The lateral mass screw length was measured using Margerl’s technique and pedicle width and pedicle screw trajectory were determined in three-dimensional reformated images. Results: CT scans of cervical spines of 94 patients were obtained and 188 lateral masses and pedicles of C7 vertebrae were measured. The mean lateral mass screw length was 13.2 mm (standard deviation [SD] 1.6 mm), mean outer pedicle width was 5.9 mm (SD 1.0 mm) and mean pedicle screw trajectory was 29.4 degrees (SD 3.6 degrees). Most (91.0%) of the pedicles had an outer diameter ≥4.5 mm. Conclusions: The mean lateral mass screw length was longer when compared with other similar studies, while the mean outer pedicle width was narrower. Nearly 10% of the pedicles were unable to accommodate 3.5 mm screws. These findings favor the use of lateral mass screws to provide a safe and stable fixation for C7 vertebrae in Southern Chinese patients, while the final choice of fixation method should only be confirmed after careful preoperative planning with CT scan.

중국어 문말조사의 통사 특징

鄭兆邦(Siu-Pong Cheng),鄧思穎(Sze-Wing Tang),林姃炫(번역자) 중국어문논역학회 2024 中國語文論譯叢刊 Vol.- No.55

Defining Optimal Surgical Treatment for Recurrent Hepatocellular Carcinoma: A Propensity Score Matched Analysis

( Ka Wing Ma ),( Kenneth Siu Ho Chok ),( Albert Chi Yan Chan ),( James Yan Yue Fung ),( Chung Mau Lo ) 대한간학회 2017 춘·추계 학술대회 (KASL) Vol.2017 No.1

Aims: Salvage liver transplantation (sLT) and repeated resection (RR) are effective treatment for recurrent hepatocellular carcinoma (HCC), comparison of the oncological outcomes between these two modalities were scarce. Methods: Consecutive patients admitted for either sLT or RR for recurrent HCC were recruited. All patients in the present series received either prior hepatectomy, ablative therapy or both before RR and sLT. Paedatric patients and patients treated by non-curative approach were excluded. Patient demographic, perioperative and outcome data were analyzed. Survival analysis was performed after propensity score matching. Results: There were 277 eligible patients recruited, 67 and 210 of them underwent sLT and RR respectively. Significant difference in preoperative haemoglobin, albumin, hepatitis B carrier status, MELD score, and tumor number were found (all P<0.001) between sLT and RR group. Multivariate analysis revealed that type of treatment (P=0.002, OR=2.13 95%CI 1.2-3.2), lapse time from last curative treatment (P=0.022, OR=0.994 95%CI 0.988-0.999), alpha fetal protein (AFP) (P=0.01 OR=1.00 95%CI 1.00-1.00) and tumor number (P<0.001, OR=1.23 95%CI 1.14-1.32) were independent factors associated with overall survival. After 1:3 PS matching, there were 36 sLT and 108 RS patients for comparison. The median age, MELD, AFP, tumor size and umber of the matched population were 57, 7.5, 16U/ml, 2.5cm and 1 respectively. There was no difference in the hospital mortality and complication rate (Clavien IIIa or above) between the groups, while the blood loss (P<0.001), operation time (P<0.001) and hospital stay (P=0.002) were significantly more in the sLT group. Patients in sLT group had significantly longer disease free (140 vs 49 months, P=0.031) and overall survival (176 vs 55.3 months, P=0.026). Conclusions: Salvage LT is superior to repeated resection for treatment of recurrent HCC and is associated with more than two fold increase in long term survival.

Design optimization of vibration isolation system through minimization of vibration power flow

Shilin Xie,Siu Wing Or,Helen Lai Wa Chan,Ping Kong Choy,Peter Chou Kee Liu 국제구조공학회 2008 Structural Engineering and Mechanics, An Int'l Jou Vol.28 No.6

A vibration power minimization model is developed, based on the mobility matrix method, for a vibration isolation system consisting of a vibrating source placed on an elastic support structure through multiple resilient mounts. This model is applied to investigate the design optimization of an X-Y motion stage-based vibration isolation system used in semiconductor wire-bonding equipment. By varying the stiffness coefficients of the resilient mounts while constraining the dynamic displacement amplitudes of the X-Y motion stage, the total power flow from the X-Y motion stage (the vibrating source) to the equipment table (the elastic support structure) is minimized at each frequency interval in the concerned frequency range for different stiffnesses of the equipment table. The results show that when the equipment table is relatively flexible, the optimal design based on the proposed vibration power inimization model gives significantly little power flow than that obtained using a conventional vibration force minimization model at some critical frequencies. When the equipment table is rigid enough, both models provide almost the same predictions on the total power flow.

Design optimization of vibration isolation system through minimization of vibration power flow

Xie, Shilin,Or, Siu Wing,Chan, Helen Lai Wa,Choy, Ping Kong,Liu, Peter Chou Kee Techno-Press 2008 Structural Engineering and Mechanics, An Int'l Jou Vol.28 No.6

A vibration power minimization model is developed, based on the mobility matrix method, for a vibration isolation system consisting of a vibrating source placed on an elastic support structure through multiple resilient mounts. This model is applied to investigate the design optimization of an X-Y motion stage-based vibration isolation system used in semiconductor wire-bonding equipment. By varying the stiffness coefficients of the resilient mounts while constraining the dynamic displacement amplitudes of the X-Y motion stage, the total power flow from the X-Y motion stage (the vibrating source) to the equipment table (the elastic support structure) is minimized at each frequency interval in the concerned frequency range for different stiffnesses of the equipment table. The results show that when the equipment table is relatively flexible, the optimal design based on the proposed vibration power inimization model gives significantly little power flow than that obtained using a conventional vibration force minimization model at some critical frequencies. When the equipment table is rigid enough, both models provide almost the same predictions on the total power flow.

Clinical Biomarkers of Neurodegeneration in REM Sleep Behavior Disorder

Junying Zhou,Jihui Zhang,Siu Ping Lam,Xiangdong Tang,Yun Kwok Wing 대한수면연구학회 2015 Journal of sleep medicine Vol.12 No.2

Rapid eye movement (REM) sleep behavior disorder (RBD) is currently considered as a prodromal stage of α -synucleinopathies neurodegeneration. The update data suggested that over 80% patients with idiopathic RBD eventually developed neurodegenerative disease after a mean of 14 years interval from the onset of RBD. A series of potential biomarkers have been identified to predict the development of neurodegeneration in idiopathic RBD, including olfactory loss, color vision deficit, depression, mild cognitive impairment, excessive daytime sleepiness, dopamine dysfunction, and tonic EMG activity. Early recognition of the predictive markers of neurodegeneration in idiopathic RBD is essential for development of intervention or prevention strategies at the presymptomatic stage. Nonetheless, the current literature is lacking biomarkers that might reflect the α-synuclein neuropathology at the earliest stages. Future studies with large samples and systematic follow-up are needed to confirm more potential markers of neurodegeneration at its early stages.

The Inaccuracy of Surface Landmarks for the Anterior Approach to the Cervical Spine in Southern Chinese Patients

Tin Sui Ko,Michael Siu Hei Tse,Kam Kwong Wong,Wing Cheung Wong 대한척추외과학회 2018 Asian Spine Journal Vol.12 No.6

Study Design: Observational study. Purpose: To assess the correlational accuracy between the traditional anatomic landmarks of the neck and their corresponding vertebral levels in Southern Chinese patients. Overview of Literature: Recent studies have demonstrated discrepancies between traditional anatomic landmarks of the neck and their corresponding cervical vertebra. Methods: The center of the body of the hyoid bone, the upper limit of the lamina of the thyroid cartilage, and the lower limit of the cricoid cartilage were selected as representative surface landmarks for this investigation. The corresponding vertebral levels in 78 patients were assessed using computed tomography. Results: In both male and female patients, almost none of the anatomical landmarks demonstrated greater than 50% correlation with any vertebral level. The most commonly corresponding vertebra of the hyoid bone, the lamina of the thyroid cartilage, and the cricoid cartilage were the C4 (47.5%), C5 (35.9%), and C7 (42.3%), respectively, which were all different from the classic descriptions in textbooks. The vertebral levels corresponding with the thyroid and cricoid cartilage were significantly different between genders. Conclusions: The surface landmarks of the neck were not accurate enough to be used as the sole determinant of vertebral levels or incision sites. Intra-operative fluoroscopy is necessary to accurately locate each of the cervical vertebral levels.

Growth of Advanced Service Firms and Usage of Quality Office Space : The Case of Hong Kong

Wadu Mesthrige Jayantha, Lau. Stephen Siu Yu, Sivaguru Ganesan, Kwok Chun Wong, Chau Kwong Wing 서울시립대학교 도시과학연구원 2007 International journal of urban sciences (IJUS) Vol. No.

This paper examines the impact of the expanding service sector in Hong Kong upon the increasing quality of office space demanded. Two measures are used to represent quality: increased usage of IT facilities in offices; and increased space per employee. The main result is that there is a significant correlation between growth of the service sector, as represented by the FIRB sector, and demand for better quality space. However, not all of the firms in the FIRB sector use/demand high quality space. The finance, business services and technology firms in Hong Kong have invested relatively heavily in IT facilities, and have also gained a higher growth relative to those with less investment in IT. Insurance and real estate firms use relatively less IT facilities. Growth of the service sector has also influenced the space usage pattern in Hong Kong. The causality analysis shows that provision of higher quality office space attracts new users.