Ky Sze - Academia.edu (original) (raw)

Papers by Ky Sze

Research paper thumbnail of FEM-based soft robotic control framework for intracavitary navigation

2017 IEEE International Conference on Real-time Computing and Robotics (RCAR), 2017

Research paper thumbnail of Design of Non-fragile H-infinity Controller for Active Vehicle Suspensions

Research paper thumbnail of Nonparametric Online Learning Control for Soft Continuum Robot: An Enabling Technique for Effective Endoscopic Navigation

Research paper thumbnail of A new assumed strain quadratic triangular C0 plate bending element

Research paper thumbnail of Creation of a tissue interface between bone-like construct and soft tissue-like construct

The 2nd TERMIS World Congress in conjunction with the 2009 Seoul Stem Cell Symposium, Seoul, Sout... more The 2nd TERMIS World Congress in conjunction with the 2009 Seoul Stem Cell Symposium, Seoul, South Korea, 31 August-3 September 2009.

Research paper thumbnail of Elimination of spurious kinematic and pressure modes in biquadratic plane element

Research paper thumbnail of Improved formulations of Qcs6 hybrid element for enhancing computational efficiency

International Journal for Numerical Methods in Engineering, 1991

This article discusses two alternative methods of formulating the recently proposed quadrilateral... more This article discusses two alternative methods of formulating the recently proposed quadrilateral plane element Qcs6, which is based on a generalized functional with multiple stress fields. The first method is derived by an extended Hu‐Washizu Principle with the presence of incompatible modes and enforcement of energy orthogonality, while the second one is established on a non‐conventional discrete local stress smoothing. Both methods can be applied to other structural element formulations with enhanced efficiency.

Research paper thumbnail of An eighteen-node hybrid-stress solid-shell element for homogenous and laminated structures

Finite Elements in Analysis and Design, 2002

Research paper thumbnail of Stabilization schemes for 12-node to 21-node brick elements based on orthogonal and consistently assumed stress modes

Computer Methods in Applied Mechanics and Engineering, 1994

ABSTRACT

Research paper thumbnail of Microplate manipulation of human mesenchymal stem cells (hMSCs)-collagen microspheres

Poster Session - Track 1 Biomaterials, Tissue Engineering and Regenerative Medicine: P1.27The 4th... more Poster Session - Track 1 Biomaterials, Tissue Engineering and Regenerative Medicine: P1.27The 4th World Congress on Bioengineering (WACBE) 2009, Hong Kong, 26-29 July 2009. In Proceedings of the 4th WACBE, 2009, p. 6

Research paper thumbnail of Correcting power-law viscoelastic effects in elastic modulus measurement using depth-sensing indentation

International Journal of Solids and Structures, 2005

The standard Oliver–Pharr method for measuring the elastic modulus by depth-sensing indentation m... more The standard Oliver–Pharr method for measuring the elastic modulus by depth-sensing indentation makes use of the unloading response of the material as it is assumed that the unloading behaviour is purely elastic. However, under certain conditions, the unloading behaviour can be viscoelastic, and if the viscosity effects are not corrected, the calculated modulus can be seriously erroneous. Feng and Ngan

Research paper thumbnail of Multifield finite element formulation for Helmholtz problem

Research paper thumbnail of Hybrid Stress Finite Element Methods for Plate and Shell Structures

Advances in Structural Engineering, 2001

This paper is a survey of the use of assumed stress hybrid finite element methods for analyzing p... more This paper is a survey of the use of assumed stress hybrid finite element methods for analyzing plate and shell structures. It describes the construction of Kirchhoff plate element by complementary energy principle, and of Reissner-Mindlin plate element by Hellinger-Reissner principle. Special hybrid stress elements are used to model joining of elements which are not coplanar. Such elements include the so-called semiLoof plate elements and 3D-solid elements tailored for analyzing thin plates and shells.

Research paper thumbnail of Incompressible material point method for free surface flow

Journal of Computational Physics, 2017

Research paper thumbnail of On the relative merits of three-point integration rules for six-node triangles

Finite Elements in Analysis and Design, 1997

Research paper thumbnail of Ha5 disturbance attenuation for uncertain mechanical systems with input delay

Research paper thumbnail of Analyzing the mechanical behavior of bio-filament networks via a combined finite element-Langevin dynamics (FEM-LD) approach

Session - Awards Symposia: Prager Medal Symposium in honor of George Weng: Micromechanics, Compos... more Session - Awards Symposia: Prager Medal Symposium in honor of George Weng: Micromechanics, Composites and Multifunctional Materials

Research paper thumbnail of Three-dimensional structural frame analysis using solid finite elements

Research paper thumbnail of Development of a Shear Test System for Measuring the Interfacial Strength of Osteochondral Grafts from Rabbits of Different Skeletal Maturity

HKIE Transactions, 2012

ABSTRACT

Research paper thumbnail of Fabrication of Multicomponent Tissue-Like Constructs-Toward Spinal Motion Segment Tissue Engineering

Global Spine Journal, 2012

Introduction Allogenic spinal motion segment transplantation demonstrated promising results in tr... more Introduction Allogenic spinal motion segment transplantation demonstrated promising results in treating late stage disk degeneration and stimulated immense interests of tissue engineering in the whole spinal motion segment from autologous cell source and safe biomaterials, solving the donor availability problem and potentially alleviating the degeneration and immunogenicity problems. Bioengineering complex tissues such as spinal motion segment is extremely challenging because it involves the integration of multiple tissues with distinct structures and composition such as lamellar annulus fibrosus (AF), gel-like nucleus pulposus (NP), cartilaginous endplate, and bony vertebra. Although attempts have been made to fabricate biphasic structures such as lamellar AF structure wrapping around a NP core, or bony block with cartilaginous structure, good methods integrating different tissue parts to form a combined unit are not available. In this study, a bioreactor-based method integrating multicomponent spinal motion segment-like tissue constructs, together with in vitro mechanical and biological stimulation, was reported, as the first step towards functional spinal motion segment tissue engineering. Materials and Methods Rabbit mesenchymal stem cells (rMSC) were used to fabricate cell-collagen constructs. Constructs were cultured separately in chondrogenic and osteogenic differentiation medium for 21 days. A layer of rMSC-collagen solution was added between chondrogenic and osteogenic units for coculture with cyclic compression to form the combined osteochondral constructs with intact interface. Afterward, an acellular cylindrical collagen gel was formed in between two such combined osteochondral constructs before circumferencing the whole construct with rMSC-collagen tubular layers. The multicomponent constructs were subjected to periodic compression and torsion simultaneously. The constructs were evaluated histologically for multicomponent structures. Cell alignment in the tubular layers was quantified using an adhoc MatLab program while collagen alignment was evaluated using scanning electron microscopy (SEM). Moreover, the interfacial strength of the osteochondral units was also evaluated using a tensile test machine. Results The combined constructs were able to be dismounted with integrity from the supporting shafts of the bioreactor after 14 days of culture. Every component of the combined constructs remained intact and can be manipulated with forceps. This method proves the feasibility to proceed to bioreactor-based functional remodelling and engineering of spinal motion segment in the future. Alignment analysis of rMSC in the tubular layers of the combined constructs demonstrated that the cell aligned along different preferred direction under torsional stimulation as compared with that from the static loading control (Fig. 1). However, SEM demonstrated no significant collagen alignment after 14 days culture for all groups. Histological results showed good integration among different components while cells were able to migrate into the acellular collagen gel at the center of the combined constructs although the source of the migrated cells was not studied yet. In addition, the osteogenic and chondrogenic phenotype in the osteochondral units were maintained while the interfacial strength of the osteochondral units was significantly higher when both the biological and the compression stimulation were present during their fabrication. Conclusion A method fabricating a multicomponent tissue construct with integrity for future functional spinal motion segment tissue engineering is demonstrated. Torsional stimulation can be used to stimulate rMSC re-orientation within a collagen tubular structure. Osteogenic differentiated and chondrogenic differentiated rMSC were able to maintain the phenotype throughout the culture period and their interface stabilized by biological and mechanical stimulation. I confirm having declared any potential conflict of interest for all authors listed on this abstract No Disclosure of Interest None declared Cheng HW, Luk KD, Cheung KM, Chan BP. In vitro generation of an osteochondral interface from mesenchymal stem cell-collagen microspheres. Biomaterials 2011;32(6):1526–1535. Au-Yeung KL, Sze KY, Sham MH, Chan BP. Development of a micromanipulator-based loading device for mechanoregulation study of human mesenchymal stem cells in three-dimensional collagen constructs. Tissue Engineering Part C Methods 2010;16(1):93–107.

Research paper thumbnail of FEM-based soft robotic control framework for intracavitary navigation

2017 IEEE International Conference on Real-time Computing and Robotics (RCAR), 2017

Research paper thumbnail of Design of Non-fragile H-infinity Controller for Active Vehicle Suspensions

Research paper thumbnail of Nonparametric Online Learning Control for Soft Continuum Robot: An Enabling Technique for Effective Endoscopic Navigation

Research paper thumbnail of A new assumed strain quadratic triangular C0 plate bending element

Research paper thumbnail of Creation of a tissue interface between bone-like construct and soft tissue-like construct

The 2nd TERMIS World Congress in conjunction with the 2009 Seoul Stem Cell Symposium, Seoul, Sout... more The 2nd TERMIS World Congress in conjunction with the 2009 Seoul Stem Cell Symposium, Seoul, South Korea, 31 August-3 September 2009.

Research paper thumbnail of Elimination of spurious kinematic and pressure modes in biquadratic plane element

Research paper thumbnail of Improved formulations of Qcs6 hybrid element for enhancing computational efficiency

International Journal for Numerical Methods in Engineering, 1991

This article discusses two alternative methods of formulating the recently proposed quadrilateral... more This article discusses two alternative methods of formulating the recently proposed quadrilateral plane element Qcs6, which is based on a generalized functional with multiple stress fields. The first method is derived by an extended Hu‐Washizu Principle with the presence of incompatible modes and enforcement of energy orthogonality, while the second one is established on a non‐conventional discrete local stress smoothing. Both methods can be applied to other structural element formulations with enhanced efficiency.

Research paper thumbnail of An eighteen-node hybrid-stress solid-shell element for homogenous and laminated structures

Finite Elements in Analysis and Design, 2002

Research paper thumbnail of Stabilization schemes for 12-node to 21-node brick elements based on orthogonal and consistently assumed stress modes

Computer Methods in Applied Mechanics and Engineering, 1994

ABSTRACT

Research paper thumbnail of Microplate manipulation of human mesenchymal stem cells (hMSCs)-collagen microspheres

Poster Session - Track 1 Biomaterials, Tissue Engineering and Regenerative Medicine: P1.27The 4th... more Poster Session - Track 1 Biomaterials, Tissue Engineering and Regenerative Medicine: P1.27The 4th World Congress on Bioengineering (WACBE) 2009, Hong Kong, 26-29 July 2009. In Proceedings of the 4th WACBE, 2009, p. 6

Research paper thumbnail of Correcting power-law viscoelastic effects in elastic modulus measurement using depth-sensing indentation

International Journal of Solids and Structures, 2005

The standard Oliver–Pharr method for measuring the elastic modulus by depth-sensing indentation m... more The standard Oliver–Pharr method for measuring the elastic modulus by depth-sensing indentation makes use of the unloading response of the material as it is assumed that the unloading behaviour is purely elastic. However, under certain conditions, the unloading behaviour can be viscoelastic, and if the viscosity effects are not corrected, the calculated modulus can be seriously erroneous. Feng and Ngan

Research paper thumbnail of Multifield finite element formulation for Helmholtz problem

Research paper thumbnail of Hybrid Stress Finite Element Methods for Plate and Shell Structures

Advances in Structural Engineering, 2001

This paper is a survey of the use of assumed stress hybrid finite element methods for analyzing p... more This paper is a survey of the use of assumed stress hybrid finite element methods for analyzing plate and shell structures. It describes the construction of Kirchhoff plate element by complementary energy principle, and of Reissner-Mindlin plate element by Hellinger-Reissner principle. Special hybrid stress elements are used to model joining of elements which are not coplanar. Such elements include the so-called semiLoof plate elements and 3D-solid elements tailored for analyzing thin plates and shells.

Research paper thumbnail of Incompressible material point method for free surface flow

Journal of Computational Physics, 2017

Research paper thumbnail of On the relative merits of three-point integration rules for six-node triangles

Finite Elements in Analysis and Design, 1997

Research paper thumbnail of Ha5 disturbance attenuation for uncertain mechanical systems with input delay

Research paper thumbnail of Analyzing the mechanical behavior of bio-filament networks via a combined finite element-Langevin dynamics (FEM-LD) approach

Session - Awards Symposia: Prager Medal Symposium in honor of George Weng: Micromechanics, Compos... more Session - Awards Symposia: Prager Medal Symposium in honor of George Weng: Micromechanics, Composites and Multifunctional Materials

Research paper thumbnail of Three-dimensional structural frame analysis using solid finite elements

Research paper thumbnail of Development of a Shear Test System for Measuring the Interfacial Strength of Osteochondral Grafts from Rabbits of Different Skeletal Maturity

HKIE Transactions, 2012

ABSTRACT

Research paper thumbnail of Fabrication of Multicomponent Tissue-Like Constructs-Toward Spinal Motion Segment Tissue Engineering

Global Spine Journal, 2012

Introduction Allogenic spinal motion segment transplantation demonstrated promising results in tr... more Introduction Allogenic spinal motion segment transplantation demonstrated promising results in treating late stage disk degeneration and stimulated immense interests of tissue engineering in the whole spinal motion segment from autologous cell source and safe biomaterials, solving the donor availability problem and potentially alleviating the degeneration and immunogenicity problems. Bioengineering complex tissues such as spinal motion segment is extremely challenging because it involves the integration of multiple tissues with distinct structures and composition such as lamellar annulus fibrosus (AF), gel-like nucleus pulposus (NP), cartilaginous endplate, and bony vertebra. Although attempts have been made to fabricate biphasic structures such as lamellar AF structure wrapping around a NP core, or bony block with cartilaginous structure, good methods integrating different tissue parts to form a combined unit are not available. In this study, a bioreactor-based method integrating multicomponent spinal motion segment-like tissue constructs, together with in vitro mechanical and biological stimulation, was reported, as the first step towards functional spinal motion segment tissue engineering. Materials and Methods Rabbit mesenchymal stem cells (rMSC) were used to fabricate cell-collagen constructs. Constructs were cultured separately in chondrogenic and osteogenic differentiation medium for 21 days. A layer of rMSC-collagen solution was added between chondrogenic and osteogenic units for coculture with cyclic compression to form the combined osteochondral constructs with intact interface. Afterward, an acellular cylindrical collagen gel was formed in between two such combined osteochondral constructs before circumferencing the whole construct with rMSC-collagen tubular layers. The multicomponent constructs were subjected to periodic compression and torsion simultaneously. The constructs were evaluated histologically for multicomponent structures. Cell alignment in the tubular layers was quantified using an adhoc MatLab program while collagen alignment was evaluated using scanning electron microscopy (SEM). Moreover, the interfacial strength of the osteochondral units was also evaluated using a tensile test machine. Results The combined constructs were able to be dismounted with integrity from the supporting shafts of the bioreactor after 14 days of culture. Every component of the combined constructs remained intact and can be manipulated with forceps. This method proves the feasibility to proceed to bioreactor-based functional remodelling and engineering of spinal motion segment in the future. Alignment analysis of rMSC in the tubular layers of the combined constructs demonstrated that the cell aligned along different preferred direction under torsional stimulation as compared with that from the static loading control (Fig. 1). However, SEM demonstrated no significant collagen alignment after 14 days culture for all groups. Histological results showed good integration among different components while cells were able to migrate into the acellular collagen gel at the center of the combined constructs although the source of the migrated cells was not studied yet. In addition, the osteogenic and chondrogenic phenotype in the osteochondral units were maintained while the interfacial strength of the osteochondral units was significantly higher when both the biological and the compression stimulation were present during their fabrication. Conclusion A method fabricating a multicomponent tissue construct with integrity for future functional spinal motion segment tissue engineering is demonstrated. Torsional stimulation can be used to stimulate rMSC re-orientation within a collagen tubular structure. Osteogenic differentiated and chondrogenic differentiated rMSC were able to maintain the phenotype throughout the culture period and their interface stabilized by biological and mechanical stimulation. I confirm having declared any potential conflict of interest for all authors listed on this abstract No Disclosure of Interest None declared Cheng HW, Luk KD, Cheung KM, Chan BP. In vitro generation of an osteochondral interface from mesenchymal stem cell-collagen microspheres. Biomaterials 2011;32(6):1526–1535. Au-Yeung KL, Sze KY, Sham MH, Chan BP. Development of a micromanipulator-based loading device for mechanoregulation study of human mesenchymal stem cells in three-dimensional collagen constructs. Tissue Engineering Part C Methods 2010;16(1):93–107.