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Wear simulation for implantable knee, hip and intervertebral spinal disc prostheses have all been well documented and standardized tests methods have been created in order to assess the performance of these medical device implants. Despite the fundamental developments in wear testing for hip, knee and spine implants there has been little focus on extremity wear testing for other medical implants. Current knowledge of wear performance in Total Ankle Replacements (TAR) and Total Shoulder Replacements (TSR) is limited which has resulted in the need for more detailed examination of the performance of these implants both under in-vivo conditions and in the laboratory.
Digital Image Correlation (DIC) is a non-contact, non-interferometric measurement technique that uses high-resolution machine-vision digital cameras to accurately measure surface deformation in two or three dimensions. This measurement is presented graphically in a number of ways such as a 2D strain map overlaying the test specimen, or a 3D displacement map showing the specimen surface and how it moves throughout the test. Early development of this technology began in the mid-1980s in the mechanical engineering department of the University of South Carolina. Since then it has gone on to revolutionize mechanical testing on both the macro and micro scale. The applications of DIC are vast, from eyeball pressure testing to earthquake analysis; this adaptable and highly capable system will transform design, validation and testing methods for anything from dental implants to wind turbines.
Digital Image Correlation (DIC) is a full-field image analysis method which employs high resolution digital cameras to track displacement occurring on the surface of an object. It has gained recognition for the potential that it possesses for a number of industries, not least among them the construction industry. This white paper focuses on potential applications for the construction industry drawing on examples of previous testing applications and highlighting the advantages DIC offers over conventional structural and materials testing methods.
With increased pressure from regulatory bodies demanding stringent testing throughout the design, validation and manufacturing phases of healthcare product development, test methods are becoming increasingly complex. Digital Image Correlation (DIC), offers in depth analysis, in a simple yet efficient and comprehensive manner.
Using high powered digital cameras and the latest high-tech software DIC provides visual and quantitative analysis of surface strains of materials and products undergoing stress testing. Highlighting the areas of high strain informs the response of a component under various loading conditions in a non-destructive way, characterizes mechanical behavior and can verify and refine finite element analysis models.
The concept of Quality by Design (QbD) is not a new idea but it is only in recent years that it has been considered for all aspects of the development process for pharmaceutical products. Even with this recent growth in interest, it can often be seen an unattractive prospect, for the reasons outlined below, and is not yet considered standard for the development of drugs and pharmaceuticals.
For those though that have taken the plunge and invested the time in developing analytical methodology for their products using QbD techniques, the advantages are being realized, reinforcing the future of QbD.
The current success, as applied to analytical test methods, relies heavily on a significant investment in laboratory time during the early stages of a product’s life cycle. For many, spending vital time designing a method from scratch instead of it being developed from a template of a similar product seems too time consuming and counterproductive. The time spent on design does, however, offer many advantages in terms of quality control and understanding of the methodology; this, in itself, provides long-term time and cost advantages.
For decades, total hip and knee replacement surgery has been successful in restoring the normal function of articulating joints. Whether the joint has been damaged through injury or as a result of arthritis, total joint replacements are some of the most common and successful orthopedic surgeries in the world.
With approximately 160,000 total hip and knee replacements being performed in over 400 hospitals each year in the UK alone, and that number set to rise by 673 percent in the next 20 years, the design of implants, as well as the materials used in them, has become the focus of many large multinational companies. The resulting technological evolution and concurrent influx of innovative devices have increased the demand for both device and materials testing solutions.
In this white paper we will look at why the testing of implants is so important. Traditional test methods and their limitations will be detailed and adverse event testing, including impingement testing and third body wear testing will be discussed.
The CDC (Centres for Disease Control and Prevention) now considers prescription drug abuse in the US an epidemic. Abuse in these cases can be defined as the intentional misuse of pharmaceuticals to deliver a desirable physiological and psychological effect. These drugs are abused via several known routes, including chemical tampering or crushing followed by insufflation, intravenous intake or via oral abuse, using greater than prescribed doses.
Driven by public health, governmental and regulatory bodies, such as the Food and Drug Administration (FDA), vast investment has already been made into reduction of abuse and misuse of prescription drugs. The abuse deterrence of prescriptions, particularly in the case of opioids, is a key area of concern and, as a result, a growing market has emerged.
This paper explores the market drivers for abuse deterrence and identify possible solutions.
Composites are being used more and more in many different industries, thanks to the enhanced properties that are realised from the combining of materials.
In this guide we will look at what composites are, highlighting their advantages and explaining how they work. We will also consider how to design with composites and how to test composites and components to ensure that they perform to the best of their ability.
The orthopedic implant industry is in a continual state of development, witnessing an explosion of novel materials, designs, and applications. This process is, however, often laced with challenges and articulating joints can present the greatest number of these. The biocompatibility of an orthopedic implant is essential but, as an increased number of patients outlive the life expectancy of their implant; longevity is becoming a significant clinical problem. Thus, the bio-tribological performance of an implant becomes increasingly relevant.
Bio-tribology is the study of friction, lubrication and wear as they occur in the human body and, as such, are all important factors to consider in the design of implants. Assessment of an implant covers three areas - mechanical testing, debris analysis and surface analysis. In this paper we will review the key techniques available, focusing on the value of generating a complete picture and an understanding of an orthopedic implant in terms of how the design, base material or coating behaves under friction and loading.
The surface characterisation of hair fibres can deliver important insights into the performance of hair care products and in the development of improved product formulations based on an understanding of the connection between product use and the resulting surface properties of the treated hair fibres. This paper reviews the range of relevant hair properties together with the use of topographical and chemical surface characterisation techniques for their determination. Non-contact white light interferometry and 3D scanning electron microscopy are used to investigate topographical consequences such as scale height and hair damage. These techniques provide statistically based metrology of hair surfaces either parametrically or as quantified 3D images. In addition we describe the application of chemical surface analysis techniques including X-ray Photoelectron Spectroscopy (XPS) and Secondary Ion Mass Spectrometry (SIMS) to the determination of chemical residues and natural substrates in terms of material identification, level quantification and spatial distribution. In all cases practical applications are described.
This paper describes how electron microprobe analysis has been used effectively in industrial materials problem solving. Three case studies are briefly presented to illustrate how the unique capabilities of the electron microprobe were used to solve each problem quickly and cost effectively. These examples illustrate how a methodical approach to problem solving, microchemical analyses, and collaboration in a cross-functional team have led to rapid identification of root cause, and successful recovery from difficult situations. Finally, guidelines are offered on some points to consider when facing problems with materials or processes.
In the manufacture of healthcare products and medical materials, especially ceramic materials like zirconia (used as an implant material) and hydroxyapatite (synthetic bone replacement material), there is often a stage in the manufacturing process involving a powder suspension. The behaviour of this powder suspension will correlate strongly to (a) how well it is processed and therefore (b) final yields and product performance. Surface chemistry dominates the particle-particle interactions in suspension, with different materials having different surface charges. These interactions in turn dictate suspension rheology. Zeta potential is used to investigate and monitor the surface interactions in powder suspensions, and can also be used to optimise the processing method. In a previous white paper, 'The Applications of Zeta Potential in Process Control', the in-depth theory of zeta potential was presented and discussed. This white paper will discuss its applications for the manufacture of certain healthcare materials and how Lucideon has assisted manufacturers in this area.
Powders play a very important role in many different areas of healthcare, most importantly in dentistry and orthopaedic materials, where they become either coatings or 3D structures. As many powder materials exist as suspensions in the early stages of their manufacturing, powder surface chemistry (and associated charge) can strongly influence suspensions’ rheological properties, and so the quality of subsequent processing. This can have dramatic effects on the quality of any end products and can lead to failure of these products. Given that powder surface charge is so critical, zeta potential becomes a crucial measurement for characterising and then optimising suspension behaviour. Zeta potential is essentially the energy required to shear a particle and associated ions away from a bulk solution. From these values, the stability of the system can be established: whether the particles are well dispersed and stable, or flocculated and unstable. This paper will discuss the theory of zeta potential, and how it can be measured and controlled. The particular advantages of using the ZetaProbe® apparatus available at Lucideon will also be discussed.
Gaining and maintaining regulatory approval of medical devices and materials, such as Hydroxyapatite (HA) can be a fraught, lengthy and complex process. Submission of data to regulatory bodies, for example the FDA (Food and Drug Administration), has to be credible and fully documented in order to ensure success. Post-regulatory approval testing is also important, not only to confirm that regulatory standards are continuing to be kept but also that consistency, quality and performance are being maintained.
In this white paper we look at the case for using one supplier for regulatory approval testing, using the example of HA testing.
Due to the ageing UK population, increased dynamism of people's lives and growing life expectancy, there is an increasing clinical demand for bone replacement and repair. The main mineral component of bone tissue is a nonstoichiometric carbonated multi-substituted apatite with calcium to phosphorus ratio (Ca:P) between 1.37 and 1.87. Synthetic hydroxyapatite is a popular bone replacement material because it has a similar crystal structure (Ca:P ratio fixed at 1.67) to native bone apatite. This resemblance is the origin of the excellent compatibility that HA exhibits with hard tissue and its natural bioactive behaviour; enabling it to be incorporated into the body via the same processes active in the remodelling of healthy bone.
Although polymers have been the most widely used material in the pharmaceutical and medical devices industry for many years, they are still often the root cause of many problems, such as unexpected product failure or yield deterioration. This is usually down to the complexity of polymeric materials. Chemical and physical structure can change at any stage - during manufacturing, post treatment (e.g. during sterilization), in storage, transportation or in use. The resulting changes in structure, which can range from the nano and micro up to millimetre scales, consequently affect the performance of the product. What’s more, product failures are often due to several co-existing factors. It is important, therefore, to understand the factors that can affect a polymer’s structure and, hence, its properties.
This paper will introduce the basic concepts regarding the structure and properties of polymeric materials. It will be of particular interest to engineers, technologists, scientists, technical managers and QA/QC professionals; anyone who is involved in developing new products or finding root causes of failures.
Much research has been done into developing synthetic Hydroxyapatite (HA) as materials for bone replacement, due to the fact that natural bone comprises HA. In addition, HA powders have been used as coatings on metal implants in a bid to make them more compatible with the body and to promote stronger bone-to-implant bonding and hence increased longevity of the implant (for example, in the case of femoral hip implants). This paper explores the role of (multi-element) substitution in HA and how this can impact on behaviour of HA in aqueous physiological environments.
Investment or 'lost wax' casting is a key process in the manufacture of high quality engineering components such as orthopaedic implants. The process may be applied to a wide range of metals and alloys and can be used to produce both large and small castings. The application of investment casting has seen significant growth in the last 5 years with estimates placing the current market size at $US 8.6 billion and whilst US remains the largest single producer, Asian markets account for approx 35% of this value.
This white paper examines the major issues involved with the investment casting process. The problems that can occur during pattern manufacture, shell moulding, de-waxing and casting are discussed and solutions to these problems are identified. The white paper also looks at some of the non-technical issues facing investment casting in 2011 and the future.
Stents are expandable meshed tubes used either to reinforce body vessels possessing weak walls or to increase the internal diameter of a body vessel to allow an improved flow of fluids such as blood or urine. The use of arterial stents in particular has grown significantly over the last 20 years due to an ageing population and to a change in diet which has led to an increase in cardiovascular illness. Estimates vary, but it is predicted that coronary stents will have a market value of $7.2bn by 2012 and will continue to grow at a rate of 6% per annum thereafter. In 2009 over a million US citizens received angioplasty/stent interventions.
In this paper we will review some of the technology being used in the development of new stents and how, in particular, computational modelling and material characterisation are helping to improve clinical outcomes. Finally we will look at the future perspectives for next generation stent technology.
The complexity of PCB manufacturing has increased dramatically over the last three decades and, with this increase in complexity, the possibility of manufacturing defects has also consequently increased. Solving these failures quickly, so as to minimise downtime, is obviously critical. This is where surface analysis techniques come into play as they are able to provide high spatial resolution, low detection limits and molecular information that analytical equipment found in-house cannot provide. This white paper will discuss some of the surface analysis techniques available and give case study examples, showing where the techniques have been able to solve failure problems and help manufacturers to improve their processes.
Secondary Ion Mass Spectrometry (SIMS) is one of the most important characterisation tools in the semiconductor industry. SIMS has several key features which specifically benefit the industry.
Semiconductor device technology continues to advance with scaling to smaller dimensions, allowing for greater device density and higher switching speeds. As the technology has moved through the 130, 90 and 65nm nodes there has been a consequential demand for new materials to counteract the effects of shrinking dimensions.
At the same time, developments in solar research and optoelectronics have also produced a new range of compound semiconductorbased devices with complex thin layer structures.
Lucideon has developed a range of analytical protocols using SIMS and other techniques to provide those in the semiconductor and related industries with solutions to problems in product development, process improvement, reverse engineering and failure analysis. This paper summarises a range of typical applications relevant to the semiconductor industry.
Residues on the surface of medical devices can cause implant failure and poor device performance. The main source of these residues is from materials used in the manufacture of the device, although contamination during the storage, cleaning and handling of the device is also known to occur. Small amounts of these surface residues can cause deleterious effects in patients, because the residues are in direct contact with body tissues and patients often have compromised immune systems. In addition, residues may often alter the surface chemistry and geometry of the device, so even inert residues can be a problem. For example, small amounts of non-toxic cutting fluid on an implant limit the ability of surrounding tissues to attach to the implant.
In order to minimise contamination, the Federal Drug Administration (FDA) stipulates that medical device manufacturers follow specific cleanliness validation procedures. Firstly, they must identify all possible residues present on the device and set an acceptable residue limit. Then, they must use a cleaning regime that reduces residue levels below this limit, without leaving significant levels of cleaning agent behind. Finally documentation to verify that residue limits are not exceeded must be submitted to the FDA before the device can go on the market.
Despite these procedures being in place, some medical devices are failing to meet FDA requirements for cleanliness verification and validation. Since 2001, 173 medical devices have been recalled, some due to contamination issues. In just one year of sterility inspections, more than 483 FDA observations related to validation deficiencies - more than any other deficiency.
Surface Analysis is assisting the pharmaceutical industry in a number of ways, including for example the optimisation and acceleration of new product development, evaluation of product and packaging stability, rapid identification of trace contamination and quality assessment of new manufacturing processes. And it is certain that Surface Analysis can illuminate much more about processes, and even origins, in this sophisticated marketplace - including by helping detect counterfeits. Developments at the forefront of Surface Analysis technology are so powerful that it is enabling an independent UK research centre to materially assist pharmaceutical companies in their battle against counterfeit drugs.
Not only does this technology - the latest in X-ray Photoelectron Spectroscopy (XPS) and Time-of-Flight Secondary Ion Mass Spectrometry (ToFSIMS) in particular - afford a means of analysing the composition of various pharmaceuticals, recent work has also shown that it can even determine differences in the manufacturing processes involved, enabling the identification of previously undetectable chemical copies.
Traditionally, one thinks of Surface Analysis as being concerned principally with the physical properties of surfaces - flatness, roughness, colour, reflectivity and so on. The state-of-theart in this area is '3D non-contact profiling', where white light interferometry techniques allow examination of ‘microfeatures’. Areas from a few square microns up to the centimetre scale can be analysed with nanometre resolution.
With the construction industry facing one of its toughest times to date, anyone involved in design and build, whether for new construction projects or for the refurbishment of existing buildings, is looking to reduce costs, particularly costs associated with materials and length of construction.
This white paper examines the valuable role that testing can play in relation to reducing such construction costs. The advantages of testing over following traditional Codes of Practice are outlined and examples from Lucideon given as to how testing can be implemented throughout the design, construction, handover and refurbishment stages.
ISO 13356 "Implants for surgery – Ceramic materials based on yttria-stabilised tetragonal zirconia (Y-TZP)" is a standard created to ensure consistent performance of Yttria- Stabilised Zirconia (YSZ) ceramics in implants for surgery. The pass limits set can already meet or be exceeded using existing, mainstream processing routes. However, with the average age of humans increasing (resulting in over-65s making up a higher percentage of the population), there is a challenge to increase the lifetime of zirconia implants towards 30 years or more. This white paper highlights some of the testing involved in ISO 13356 and discusses how recent and on-going research into ceramic processing provides opportunities to meet the challenge.
Over the last 20 years the demands of the Aerospace and Defence sectors on materials have consistently focussed on low density (leading to lightweight components), high specific strength and/or stiffness (maximising the performance of the lightweight materials), and high hardness (for wear resistance and ballistic protection). Reducing the weight of aerospace components has obvious benefits in terms of increasing the effectiveness of the fuel burned, either in increasing the range or allowing greater payload to be carried for the same amount of fuel. In defence applications, a weight reduction of personal protection (armour/helmet etc) reduces the load on the individual soldier, allowing him to carry more munitions making him more effective, and increasing his agility and manoverability. Similarly, military vehicles benefit from reduced weight, making them more easily transported (airlifted) into the theatre of operations. However, these weight reductions must not be achieved at the expense of performance - hence the sector’s drive for new, lightweight, high performance materials.
Metals and anions that initiate or accelerate corrosion are of concern in evaluating the suitability of a non-metallic material for use in a nuclear reactor environment. This paper describes several analysis techniques for measuring concentrations of these detrimental elements. Chemical analysis for halogens, sulfur, and low-melting point metals by ASTM D129, E144 and D3761, using oxygen bomb or water leaching preparation with ion chromatography (IC) and inductively-coupled plasma (ICP) optical emission spectroscopy (OES or AES) is described. Some independent testing laboratories are approved for testing materials for use in nuclear safety-related applications. Guidelines are offered for selecting a suitable lab, whose quality and reporting standards must be in compliance with 10 CFR 50 Appendix B and 10 CFR Part 21 federal requirements.