articles+ search results

Orthopedic surgery -- Methods, Orthopedic surgery -- Analysis, Rapid prototyping -- Methods, and Rapid prototyping -- Analysis

To access, purchase, authenticate, or subscribe to the full-text of this article, please visit this link: http://dx.doi.org/10.1142/S0219519415400503 Byline: LI-QIANG ZHI, MENG LI, KAI LIU, XING MA Advanced three-dimensional (3D) models have played more and more essential roles in orthopedics surgical interventions. In order to improve the clinical outcomes of knee surgery (KS) including minimally invasive knee surgery (MIKS), the melted extrusion modeling (MEM), a rapid prototyping (RP) technique, was used efficiently to fabricate real life-size 3D physical models of interesting knees. The applications and advantages of the tangible RP-constructed 3D models in KS were elucidated in this study. As a result, better preparation including optimal preoperative planning was made so that KS could be performed in an accurate, safe and fast manner for each case. Besides, the surgical skills of MIKS were substantially improved. Therefore, the results suggest that KS can benefit much from the advanced 3D modeling technique.

Tissue engineering -- Analysis and Rapid prototyping -- Analysis

To access, purchase, authenticate, or subscribe to the full-text of this article, please visit this link: http://dx.doi.org/10.1142/S0219519411004848 Byline: CHIH-HAO CHEN, JYH-PING CHEN, MING-YIH LEE The purpose of this study was to investigate the attachment and proliferation of cells on selective laser-sintered (SLS) polycaprolactone (PCL) scaffolds coated with gelatin for cartilage tissue engineering using chondrocytes isolated from the articular cartilage of swine. Scaffolds without modification were used as control groups. Cell proliferation was measured by cell count 1, 3 and 5 days after cell seeding into the scaffolds. The biocompatibility of the scaffold was examined by scanning electron microscopy (SEM). The PCL scaffolds coated with gelatin had higher hydrophilicity. The results provided a useful strategy for modifying the microenvironments to increase cell attachment, growth and the formation of extracellular matrix on scaffolds for cartilage tissue engineering.

CAD/CAM software, CAD software, Computer-aided design -- Analysis, Rapid prototyping -- Analysis, CAD-CAM systems -- Computer programs, and CAD-CAM systems -- Analysis

To access, purchase, authenticate, or subscribe to the full-text of this article, please visit this link: http://dx.doi.org/10.1142/S021951941550058X Byline: MORSHED ALAM, IMTIAZ AHMED CHOUDHURY, AZUDDIN BIN MAMAT, SAJJAD HUSSAIN Traditional design and manufacturing methods of ankle foot orthosis (AFO) involve manual techniques e.g., casting and molding of the limbs and often depend on trial and error. Three-dimensional scanning allows computer aided design (CAD) tools to be incorporated, however, both approaches rely on the external model of the limb. To design AFO with articulated joint, precise alignment of mechanical and anatomical joint axes is imperative. It is difficult to infer joint axis from external model as it is partially specified by the skeletal structure. In this article, a computer integrated design approach of an articulated AFO has been demonstrated. CAD model of the AFO was developed for a healthy subject's left leg based on the 3D models of skeleton and soft tissue of the limb. Components of the AFO were fabricated by rapid prototyping and CNC machining. The design approach is faster than the traditional techniques and also facilitates exact positioning of articulated ankle joint. The gait analysis indicates that the subject's ankle had to overcome lesser resistance with the custom made AFO compared to a pre-fabricated AFO. Simultaneous viewing of exterior and skeletal geometry might help the clinicians modify the design to enhance performance of the orthotic.

Finite element method -- Analysis and Microfluidics -- Analysis

To access, purchase, authenticate, or subscribe to the full-text of this article, please visit this link: http://dx.doi.org/10.1142/S0219519415400436 Byline: HAO SUN, ZHANDONG LI, JIANGUO TAO Microfluidics technology has emerged as an attractive approach in physics, chemistry and biomedical science by providing increased analytical accuracy, sensitivity and efficiency in minimized systems. Numerical simulation can improve theoretical understanding, reduce prototyping consumption, and speed up development. In this paper, we setup a 3D model of an integrated microfluidic system and study the multi-physical dynamics of the system via the finite element method (FEM). The fluid--structure interaction (FSI) of fluid and an immobilized single cell within the cell trapping component, and the on-chip thermodynamics have been analyzed. The velocity magnitude and streamline of flow field, the distribution of von Mises stress and Tresca stress on the FSI interface have been studied. In addition, the on-chip heat transfer performance and temperature distribution in the heating zone have been evaluated and analyzed respectively. The presented approach is capable of optimizing microfluidic design, and revealing the complicated mechanism of multi-physical fields. Therefore, it holds the potential for improving microfluidics application in fundamental research and clinical settings.

To access, purchase, authenticate, or subscribe to the full-text of this article, please visit this link: http://dx.doi.org/10.1142/S0219519415500049 Byline: E. DOUTEL, J. CARNEIRO, M. S. N. OLIVEIRA, J. B. L. M. CAMPOS, J. M. MIRANDA 3D mili-scale channel representing simplified anatomical models of blood vessels were constructed in polidimethylsiloxane (PDMS). The objective was to obtain a sequential method to fabricate transparent PDMS models from a mold produced by rapid prototyping. For this purpose, two types of casting methods were compared, a known lost-wax casting method and a casting method using sucrose. The channels fabricated by both casting methods were analyzed by Optical Microscopy, Scanning Electron Microscopy (SEM), and Energy Dispersive X-ray Spectroscopy (EDS). The lost-wax method is not ideal since the channels become contaminated during the removal process. The models produced with the lost-sucrose casting method exhibit much better optical characteristics. These models are transparent with no visible contamination, since the removing process is done by dissolution at room temperature rather than melting. They allow for good optical access for flow visualization and measurement of the velocity field by micro-Particle Image Velocimetry ([micro]PIV). The channels fabricated by the lost-sucrose casting method were shown to be suitable for future hemodynamic studies using optical techniques.

Tissue engineering, Sintering, Polymers, and Polymer industry

To access, purchase, authenticate, or subscribe to the full-text of this article, please visit this link: http://dx.doi.org/10.1142/S0219519411004885 Byline: MING-YIH LEE, SI-WEN LIU, JYH-PING CHEN, HAN-TSUNG LIAO, WEN-WEI TSAI, HSIU-CHEN WANG Bone defects caused by tumors, diseased infection, trauma or abnormal bone development create a lot of serious health problems. Tissue engineering aims to fabricate tissues or organs using patients' cells for repairing the damaged tissues or organs in clinic. The aim of this study was to design and fabricate polycaprolactone (PCL) scaffolds using the inhouse-built selective laser sintering (SLS) rapid prototyping (RP) machine and combining with polymer hydrogel for in vitro study for bone repair. In this study, three configurations of scaffolds structure (0/45/0/45[degrees], 0/90/0/90[degrees], and 0/45/90/135[degrees] patterns) were designed and produced. The compressive modulus, porosity and pore size of porous scaffolds were first determined. In addition, polymer hydrogel was combined with PCL scaffolds with three loading methods (i.e., immersion method, injection method and titration method) to enhance scaffolds surface hydrophilicity for cell proliferation. Mesenchymal stem cells from New Zealand White rabbits were loaded on PCL scaffolds and induced to osteoblasts in vitro. Bone formation was determined by MTS assays, von Kossa stains and ALP activities. The experimental results showed the compressive moduli of scaffolds with 0/45/0/45[degrees], 0/90/0/90[degrees], and 0/45/90/135[degrees] patterns was 2 MPa, 3.4 MPa, and 3.75 MPa, respectively. The porosity of scaffolds was 72%, 76%, and 83%, respectively. The ranges of pore size of scaffolds were 350--400 [micro]m, 400--500 [micro]m, and 350--400 [micro]m, respectively. By comparing three kinds of polymer hydrogel loading methods, titration method had the best result. The in vitro experimental results revealed that OD values of MTS tests and ALP activities increased from day 7 to day 21 and von Kossa stain revealed dark brown mineralized tissue, indicating cells could proliferate and differentiate in polymer hydrogel and scaffolds.

Company legal issue, Robotics industry, Robot, Surgery -- Investigations, Robotics industry -- Investigations, Robotics -- Investigations, Robots -- Investigations, and Robotic surgery -- Investigations

To access, purchase, authenticate, or subscribe to the full-text of this article, please visit this link: http://dx.doi.org/10.1142/S0219519411004289 Byline: HONGLIANG REN, MAX Q.-H. MENG Off-the-shelf industrial robotic technologies have achieved significant advancements in the past several decades in terms of mechanics and automation performances. We are expecting to take advantage of the industrial robots for assisting surgeons in surgeries and quick prototyping a robotic surgery system. In precise computer-assisted surgeries (CASs), such as pelvic-acetabular surgery, eye surgery, or neurosurgery, it is extremely important to position the tools accurately and precisely for surgical operations. Some of the industrial robotics arms are able to achieve good repeatability and dexterity while positioning the surgical tools. To enable the application of industrial robots in the surgical rooms, there are several other essential modules to be integrated to the robotic surgery systems, such as real-time navigation system, surgical planning system, and surgeon-guidance system. In this paper, we review the existing studies on the medical robots including the ones using industrial robots, and then investigate the essentials for using industrial robots in computer-integrated surgery.