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Soo Leong Foo

Bio: Soo Leong Foo is an academic researcher. The author has contributed to research in topics: Surgical instrument & Vickers hardness test. The author has an hindex of 2, co-authored 6 publications receiving 29 citations.

Papers
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Journal ArticleDOI
TL;DR: Vickers hardness and differential scanning calorimetry (DSC) techniques were used to characterize the effects of sterilization and results exhibited no significant change in the degree of cure and melting behavior of PEEK before and after the sterilization.
Abstract: The effects of the sterilization process have been studied on medical grade thermoplastic polyetheretherketone (PEEK). For a reusable medical device, material reliability is an important parameter to decide its lifetime, as it will be subjected to the continuous steam sterilization process. A spring nature, clip component was selected out of a newly designed medical device (patented) to perform this reliability study. This clip component was sterilized for a predetermined number of cycles (2, 4, 6, 8, 10, 20…100) at 121 °C for 30 min. A significant decrease of ~20% in the compression force of the spring was observed after 30 cycles, and a ~6% decrease in the lateral dimension of the clip was observed after 50 cycles. No further significant change in the compression force or dimension was observed for the subsequent sterilization cycles. Vickers hardness and differential scanning calorimetry (DSC) techniques were used to characterize the effects of sterilization. DSC results exhibited no significant change in the degree of cure and melting behavior of PEEK before and after the sterilization. Hardness measurement exhibited an increase of ~49% in hardness after just 20 cycles. When an unsterilized sample was heated for repetitive cycles without the presence of moisture (121 °C, 10 and 20 cycles), only ~7% of the maximum change in hardness was observed.

24 citations

Journal ArticleDOI
TL;DR: The interaction forces involve during the needle insertion into porcine back tissue and simulated flesh-like tissue are presented, independently measured by a testing setup developed for this purpose and estimate the true insertion depth of the needle in the tissue.
Abstract: Needle insertion for minimally invasive surgery is a technique explored and studied in order to adhere to the strict regulatory requirement for medical device development. While the instruments and techniques determine the success of every surgical procedure, minimal attention was given to the medium, the interaction force for testing, the development tools and surgical techniques. In this paper, we present the interaction forces involve during the needle insertion into porcine back tissue and simulated flesh-like tissue, independently measured by a testing setup developed for this purpose. The experimental setup and test procedure provides an understanding on the mechanics of needle insertion, potentially aid the design improvement on surgical instrument. Investigation on the composition of the force components helps to define the bio-mechanical properties of back abdomen tissue upon insertion. These forces comprises of stiffness, friction and cutting force. These results estimate the true insertion depth of the needle in the tissue. Needle insertion forces were measured for gelatine analogues developed to model the consistency of the tissues in the lumbar region of the back. This study was the first step in developing a force feedback controlled surgical instrument for needle insertion which will be used in kidney surgical operation.

18 citations

Journal ArticleDOI
TL;DR: This study addresses the interaction by studying the needle deflection during the insertion into porcine back tissue and simulated flesh-like tissue and provides an understanding on the mechanics of needle insertion, potentially aid the design improvement on surgical instrument.
Abstract: —Needle insertion for minimally invasive surgery is a technique explored and studied for percutaneous procedure, diagnosis, localized therapeutic drug delivery, and Biopsy. While the instruments and techniques determine the success of every surgical procedure, minimal attention was given to the medium, the interaction between the tissue and the needle, the development tools and surgical techniques. This paper addresses the interaction by studying the needle deflection during the insertion into porcine back tissue and simulated flesh-like tissue. A customized testing setup is developed to measure and quantify these interactions. The needle deflection magnitude and its insertion characteristics were measured and correlated to define the bio-mechanical properties of back abdomen tissue upon insertion. Needle deflections were measured for gelatine analogues developed to model the consistency of the tissues in the lumbar region of the back. This study was the first step in developing a deflection feedback controlled surgical instrument which enable the needle to reach its intended target in the percutaneous operation. The experimental setup and test procedure provides an understanding on the mechanics of needle insertion, potentially aid the design improvement on surgical instrument.

2 citations

Journal ArticleDOI
TL;DR: This study was the first-step in developing a deflection feedback controlled surgical instrument in the needle-assisted percutaneous operation and provided understanding on the mechanics of needle insertion.
Abstract: Needle insertion for minimally-invasive surgery is a technique explored and studied for percutaneous procedure, diagnosis, localised therapeutic drug-delivery, and biopsy. While the instruments and techniques determine the success of every surgical procedure, minimal attention was given to the medium, interaction between tissue and needle, development tools and surgical techniques. This paper addresses the interaction by studying the needle deflection during insertion into porcine back tissue and simulated flesh-like tissue (gelatine). A customised testing set-up measures and quantifies these interactions. Needle deflection magnitude and insertion forces were measured and correlated to define the bio-mechanical properties of back abdomen tissue. Needle deflections were measured for gelatine analogues developed to model consistency of the tissues in the back lumbar region. Mathematical two-dimensional (2D) force-model was developed to provide understanding on the mechanics of needle insertion. This study was the first-step in developing a deflection feedback controlled surgical instrument in the needle-assisted percutaneous operation.

1 citations

Patent
08 Apr 2021
TL;DR: An instrument holder and a method for aligning an instrument for accessing a target within a subject are disclosed, wherein the instrument holder comprises a first layer, a second layer, an instrument guide with an entry and an exit point that connects between the two layers and also guide the instrument from the entry point to the exit point, and wherein the first and second layers include markings that are visible by the imaging system and form a predefined pattern when the first layer and second layer are aligned.
Abstract: An instrument holder and a method for aligning an instrument for accessing a target within a subject are disclosed, wherein the instrument holder comprises a first layer, a second layer, an instrument guide with an entry and an exit point that connects between the two layers and also guide the instrument from the entry point to the exit point, and wherein the first layer and second layer include markings that are visible by the imaging system and form a predefined pattern when the first layer and second layer are aligned. In another embodiment, the instrument guide is located within the second layer and the first layer include markings that are visible by the imaging system and also form a predefined pattern with the instrument visible by the imaging system when the first layer and second layer are aligned. Preferably, the markings are radio-opaque and/or are in form of lines, linear graduations, arrows or arrow heads or cross-hairs.

Cited by
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Journal ArticleDOI
TL;DR: The state-of-the-art of the different materials and AM techniques used for the fabrication of 3D-printed scaffolds in the field of bone tissue engineering are reviewed and some barriers impeding the translation to human clinics are identified.
Abstract: Additive manufacturing (AM) allows the fabrication of customized bone scaffolds in terms of shape, pore size, material type and mechanical properties. Combined with the possibility to obtain a precise 3D image of the bone defects using computed tomography or magnetic resonance imaging, it is now possible to manufacture implants for patient-specific bone regeneration. This paper reviews the state-of-the-art of the different materials and AM techniques used for the fabrication of 3D-printed scaffolds in the field of bone tissue engineering. Their advantages and drawbacks are highlighted. For materials, specific criteria, were extracted from a literature study: biomimetism to native bone, mechanical properties, biodegradability, ability to be imaged (implantation and follow-up period), histological performances and sterilization process. AM techniques can be classified in three major categories: extrusion-based, powder-based and liquid-base. Their price, ease of use and space requirement are analyzed. Different combinations of materials/AM techniques appear to be the most relevant depending on the targeted clinical applications (implantation site, presence of mechanical constraints, temporary or permanent implant). Finally, some barriers impeding the translation to human clinics are identified, notably the sterilization process.

76 citations

Journal ArticleDOI
TL;DR: In this article, a graphene oxide (GO) reinforced PEEK nanocomposites with different GO loading have been prepared by injection molding, and the results showed that the addition of GO into PEEK favors the adhesion and spreading of bone marrow stromal stem cells.

48 citations

Journal ArticleDOI
TL;DR: In this paper, PEEK-based filaments containing 10% of pure nano-hydroxyapatite (HA), strontium (Sr)-doped nano-HA and Zinc (Zn)-drained nano-PAatite were produced via hot-melt extrusion and subsequently 3D printed via fused deposition modelling (FDM), following an initial optimization process.
Abstract: Polyetheretherketone (PEEK) is a biocompatible polymer widely used for biomedical applications Because it is biologically inert, bioactive phases, such as nano-hydroxyapatite (HA), have been added to PEEK in order to improve its bioactivity 3D printing (3DP) technologies are being increasingly used today to manufacture patient specific devices and implants However, processing of PEEK is challenging due to its high melting point which is above 340 °C In this study, PEEK-based filaments containing 10 wt% of pure nano-HA, strontium (Sr)- doped nano-HA and Zinc (Zn)-doped nano-HA were produced via hot-melt extrusion and subsequently 3D printed via fused deposition modelling (FDM), following an initial optimization process The raw materials, extruded filaments and 3D printed samples were characterized in terms of physicochemical, thermal and morphological analysis Moreover, the mechanical performance of 3D printed specimens was assessed via tensile tensing Although an increase in the melting point and a reduction in crystallization temperature was observed with the addition of HA and doped HA to pure PEEK, there was no noticeable increase in the degree of crystallinity Regarding the mechanical behavior, no significant differences were detected following the addition of the inorganic phases to the polymeric matrix, although a small reduction in the ultimate tensile strength (~14%) and Young's modulus (~5%) in PEEK/HA was observed in comparison to pure PEEK Moreover, in vitro bioactivity of 3D printed samples was evaluated via a simulated body fluid immersion test for up to 28 days; the formation of apatite was observed on the surfaces of sample surfaces containing HA, SrHA and ZnHA These results indicate the potential to produce bioactive, 3DP PEEK composites for challenging applications such as in craniofacial bone repair

40 citations

Journal ArticleDOI
TL;DR: Additively manufactured PEEK materials showed lower Martens parameters than milled ones, whereas horizontally printed specimens presented higher values than vertically printed ones, while microscopic examinations showed that artificial aging did not cause any major modifications of the materials.

37 citations

Journal ArticleDOI
Rupak Dua1, Zuri Rashad1, Joy Spears1, Grace Dunn, Micaela Maxwell1 
22 Nov 2021-Polymers
TL;DR: A systematic review of 3D-printed polyether ether ketone (PEEK) is presented in this article, where the authors found that most of the applications are still in the research phase.
Abstract: Polyether ether ketone (PEEK) is an organic polymer that has excellent mechanical, chemical properties and can be additively manufactured (3D-printed) with ease. The use of 3D-printed PEEK has been growing in many fields. This article systematically reviews the current status of 3D-printed PEEK that has been used in various areas, including medical, chemical, aerospace, and electronics. A search of the use of 3D-printed PEEK articles published until September 2021 in various fields was performed using various databases. After reviewing the articles, and those which matched the inclusion criteria set for this systematic review, we found that the printing of PEEK is mainly performed by fused filament fabrication (FFF) or fused deposition modeling (FDM) printers. Based on the results of this systematic review, it was concluded that PEEK is a versatile material, and 3D-printed PEEK is finding applications in numerous industries. However, most of the applications are still in the research phase. Still, given how the research on PEEK is progressing and its additive manufacturing, it will soon be commercialized for many applications in numerous industries.

33 citations