Comparison of Cortical Bone Trajectory to Pedicle-Based Dynamic Stabilization: An Analysis of 291 Patients

Chih-Chang Chang,Hsuan-Kan Chang,Chin-Chu Ko,Ching-Lan Wu,Yi-Hsuan Kuo,Tsung-Hsi Tu,Wen-Cheng Huang,Jau-Ching Wu 대한척추신경외과학회 2023 Neurospine Vol.20 No.1

Objective: Pedicle-based dynamic stabilization (DS) has gained popularity outside of America. Although pedicle screw (PS) loosening has always been a concern, it is reportedly innocuous. Cortical bone trajectory (CBT) screw is an emerging option with less invasiveness and similar effectiveness to PS in short-segment lumbar fusion. This study aimed to verify the use of CBT for DS by comparing the outcomes between pedicle- and CBT-based DS. Methods: Consecutive patients with lumbar spondylosis or low-grade spondylolisthesis who underwent 1- or 2-level DS between L3–5 with a minimum follow-up of 24 months were reviewed. Screw loosening was determined by computed tomography and the incidences were compared. Results: A total of 291 patients who underwent Dynesys DS (235 pedicle- and 56 CBT-based, respectively) were compared. The demographics and preoperative conditions were similar. All the clinical outcomes improved at 24-month postoperation, while the CBT-based group had less operation time and blood loss than the pedicle-based group. The rates of screw loosening were lower in the CBT-based (5.4% per screw and 12.5% per patient) than the pedicle-based group (9% per screw and 26.4% per patient). Furthermore, there were no differences in the clinical outcomes and complication profiles. Conclusion: The CBT-based DS for 1- or 2-level lumbar degeneration demonstrated equivalent clinical improvement as the pedicle-based DS. The adaption of CBT-based screws for DS could be a less invasive approach (shorter operation time and less blood loss), with lower chances of screw loosening than the conventional PS-based DS.

High-Performance Reversible Data Hiding with Overflow/Underflow Avoidance

Ching-Yu Yang,Wu-Chih Hu 한국전자통신연구원 2011 ETRI Journal Vol.33 No.4

This paper proposes reversible data hiding using minimum/maximum preserved overflow/underflow avoidance (MMPOUA). The proposed MMPOUA algorithm consists of three main steps. These steps include the minimum (or maximum) pixel fixing, pixel squeezing, and pixel isolation. The aims of pixel fixing are to keep the minimum (or maximum) pixel of a host block unchanged and prevent the occurrence of overflow/underflow. Both the pixel squeezing and pixel isolation supply hiding storage while keeping the amount of distortion low. The proposed method can avoid (or significantly reduce) the overhead bits used to overcome overflow/underflow issues. At an embedding rate of 0.15 bpp, the proposed algorithm can achieve a PSNR value of 48.52 dB, which outperforms several existing reversible data hiding schemes. Furthermore, the algorithm performed well in a variety of images, including those in which other algorithms had difficulty obtaining good hiding storage with high perceived quality.

Passivity, Global Stabilization and Disturbance Attenuation of Weakly Minimum-Phase Nonlinear Uncertain Systems with Applications to Mechatronic Systems

Ching-Chih Tsai,Hsiao-Lang Wu 제어로봇시스템학회 2008 제어로봇시스템학회 국제학술대회 논문집 Vol.2008 No.10

Passivity and its applications to mechatronic systems have been widely investigated and continuously improved for many years. This paper presents methodologies for adaptive global stabilization and disturbance attenuation of a class of weekly minimum-phase nonlinear uncertain systems, which can be either of nonlinear affine or of relative degree 1. Adaptive passivity-based control (PBC) methods are developed to achieve adaptive stabilization and disturbance attenuation for the systems with some unknown but constant parameters. Sufficient conditions and state regulations are established for showing the closed-loop system to be globally stable. The merit and performance of the proposed methods are exemplified by conducting several simulations on a 2-linked manipulator. The developed techniques may be of interest to professionals working in the field of nonlinear passive control and its applications.

Indirect Adaptive Nonlinear Self-Balancing and Station Keeping for Omnidirectional Riding Chair

Ching-Chih Tsai,Yi-Ping Ciou,Feng-Chun Tai,Hsiao-Lang Wu 제어로봇시스템학회 2014 제어로봇시스템학회 국제학술대회 논문집 Vol.2014 No.10

This paper presents indirect adaptive self-balancing and station keeping control methods using recurrent Wavelet Fuzzy CMAC (RWFCMAC) for an omnidirectional ball-driven chair in presence of significant system uncertainties. By backstepping, sliding-mode control and RWFCMAC, the self-balancing controller is synthesized to follow the rider’s inclination angles in both two axes (x-z and y-z axis), and the station-keeping controller is designed to allow the rider to maintain the vehicle at the same place. The RWFCMAC is designed to online learning the uncertainties caused by riders’ weights and different unknown frictions between the ball and terrain surfaces. The superior performance and merit of the proposed control methods are well exemplified by comparing to two existing controllers.

Measurement of Deformity at the Craniovertebral Junction: Correlation of Triangular Area and Myelopathy

Chih-Chang Chang,Jau-Ching Wu,Chin-Chu Ko,Hsuan-Kan Chang,Yi-Hsuan Kuo,Chao-Hung Kuo,Tsung-Hsi Tu,Wen-Cheng Huang 대한척추신경외과학회 2022 Neurospine Vol.19 No.4

Objective: Diseases of the craniovertebral junction (CVJ) are commonly associated with deformity, malalignment, and subsequent myelopathy. The misaligned CVJ might cause compression of neuronal tissues and subsequently clinical symptoms. The triangular area (TA), measured by magnetic resonance imaging/images (MRI/s), is a novel measurement for quantification of the severity of compression to the brain stem. This study aimed to assess the normal and pathological values of TA by a comparison of patients with CVJ disease to age- and sex-matched controls. Moreover, postoperative TAs were correlated with outcomes. Methods: Consecutive patients who underwent surgery for CVJ disease were included for comparison to an age- and sex-matched cohort of normal CVJ persons as controls. The demographics, perioperative information, and pre- and postoperative 2-year cervical MRIs were collected for analysis. Cervical TAs were measured and compared. Results: A total of 201 patients, all of whom had pre- or postoperative MRI, were analyzed. The TA of the CVJ deformity group was larger than the healthy control group (1.62 ± 0.57 cm2 vs. 1.01 ± 0.18 cm2 , p < 0.001). Moreover, patients who had combined anterior odontoidectomy and posterior laminectomy with fixation had the greatest reduction in the TA (1.18 ± 0.58 cm2 ). Conclusion: In CVJ deformity, the measurement of the cervical TA could indicate the severity of brain stem compression. After surgery, the TA had a varying degree of improvement, which could represent the efficacy of surgery.

Scatternet Restructuring and Routing for Bluetooth Radio Systems

Chih-Yung Chang,Gwo-Jong Yu,Ching-Feng Lin,Tzu-Ting Wu 한국정보과학회 2002 한국정보과학회 학술발표논문집 Vol.2002 No.1

Research on the Throughput Impact of the Strategic Stabilizing Capacity Constraint Resources by Prolonging Planning Period

Wu, Horng-Huei,Chen, Ching-Piao,Tsai, Chih-Hung,Huang, Kuo-Wei The Korean Society for Quality Management 2009 The Asian Journal on Quality Vol.10 No.2

The issue of capacity constraint resources (CCR) or bottlenecks wandering in product mix decision by applying Theory of Constraints (TOC) management philosophy has been mentioned and demonstrated in several papers. In this study, the effect for prolonging the planning period (PPP) so as to stabilize the CCR is investigated. The results show that the effect for PPP alternative will be positive or negative which is depending on the environment condition. However, a majority cases which have positive effect for PPP alternative can be recognized prior knowing the marketing demand, which is significant in the real application.

The Option of Motion Preservation in Cervical Spondylosis: Cervical Disc Arthroplasty Update

Chih-Chang Chang,Wen-Cheng Huang,Jau-Ching Wu,Praveen V. Mummaneni 대한척추신경외과학회 2018 Neurospine Vol.15 No.4

Cervical disc arthroplasty (CDA), or total disc replacement, has emerged as an option in the past two decades for the management of 1- and 2-level cervical disc herniation and spondylosis causing radiculopathy, myelopathy, or both. Multiple prospective randomized controlled trials have demonstrated CDA to be as safe and effective as anterior cervical discectomy and fusion, which has been the standard of care for decades. Moreover, CDA successfully preserved segmental mobility in the majority of surgical levels for 5–10 years. Although CDA has been suggested to have long-term efficacy for the reduction of adjacent segment disease in some studies, more data are needed on this topic. Surgery for CDA is more demanding for decompression, because indirect decompression by placement of a tall bone graft is not possible in CDA. The artificial discs should be properly sized, centered, and installed to allow movement of the vertebrae, and are commonly 6 mm high or less in most patients. The key to successful CDA surgery includes strict patient selection, generous decompression of the neural elements, accurate sizing of the device, and appropriately centered implant placement.

An updated hip fracture projection in Asia: The Asian Federation of Osteoporosis Societies study

Ching-Lung Cheung,Seng Bin Ang,Manoj Chadha,Eddie Siu-Lun Chow,정윤석,Fen Lee Hew,Unnop Jaisamrarn,Hou Ng,Yasuhiro Takeuchi,Chih-Hsing Wu,Weibo Xia,Julie Yu,Saeko Fujiwara 대한골다공증학회 2018 Osteoporosis and Sarcopenia Vol.4 No.1

Objectives: Hip fracture is a major public health problem. Earlier studies projected that the total number of hip fracture will increase dramatically by 2050, and most of the hip fracture will occur in Asia. To date, only a few studies provided the updated projection, and none of them focused on the hip fracture projection in Asia. Thus, it is essential to provide the most up to date prediction of hip fracture in Asia, and to evaluate the total direct medical cost of hip fracture in Asia. Methods: We provide the updated projection of hip fracture in 9 Asian Federation of Osteoporosis Societies members using the most updated incidence rate and projected population size. Results: We show that the number of hip fracture will increase from 1,124,060 in 2018 to 2,563,488 in 2050, a 2.28-fold increase. This increase is mainly due to the changes on the population demographics, especially in China and India, which have the largest population size. The direct cost of hip fracture will increase from 9.5 billion United State dollar (USD) in 2018 to 15 billion USD in 2050, resulting a 1.59-fold increase. A 2%e3% decrease in incidence rate of hip fracture annually is required to keep the total number of hip fracture constant over time.

Serum and Pleural Fluid Procalcitonin in Predicting Bacterial Infection in Patients with Parapneumonic Effusion

Yang-Ching Ko,Wen-Pin Wu,Chi-Sen Hsu,Mong-Ping Dai,Chien-Chih Ou,Chih-Hsiung Kao 대한의학회 2009 Journal of Korean medical science Vol.24 No.3

This study evaluated the value of procalcitonin (PCT) levels in pleural effusion to differentiate the etiology of parapneumonic effusion (PPE). Forty-one consecutive PPE patients were enrolled and were divided into bacterial and non-bacterial PPE. Blood and pleural effusion samples were collected for PCT measurement on admission and analyzed for diagnostic evaluation. PCT of pleural fluid was significantly increased in the bacterial PPE group (0.24 ng/mL) compared to the non-bacterial PPE group (0.09 ng/mL), but there was no significant difference for serum PCT. A PCT concentration of pleural fluid >0.174 ng/mL (best cut-off value) was considered positive for a diagnosis of bacterial PPE (sensitivity, 80%; specificity, 76%; AUC, 0.84). Pleural effusion PCT in the bacterial PPE is significantly different from those of the non-bacterial PPE and control groups, so the diagnostic use of PCT still warrants further investigation.