Design and additive manufacturing of a patient specific polymer thumb splint concept

Traditionally, upper limb splints often fall short of being optimal with respect fit and patient expectations, resulting in a lack of use and no treatment of the underlying condition. In this study we address several current limitations and examine the feasibility of using 3D optical scanning, Computer Aided Design (CAD) and low cost 3D printing as a tool to create more ergonomic and efficacious splints for patients suffering from compromised musculature or trauma of the thumb. Optical scanning allows for a non-invasive and rapid means to reproduce the surface topology of a person's hand and this data was used as the template for the device design. We explore the use of CAD to create a more aesthetically pleasing and functional splint, enhancing both comfort and potential moisture release. Finally, we demonstrate that low cost polymer printing can allow for rapid design evaluation and production of a final, usable device

Development of virtual surgical planning models and a patient specific surgical resection guide for treatment of a distal radius osteosarcoma using medical 3D modelling and additive manufacturing processes

In this study we will assess the design and fabrication of a patient-specific resection guide to augment surgical procedures, such as bone grafts and implant placement. Medical imaging data was used to form a 3-dimensional, digital template model of the target anatomy to incorporate surface topography information into the guide. The surgical guide was then designed to incorporate slots for bone cutting, holes for drilling of fixation points, and an optimised geometry which ensure ease of placement and use. The final device was then manufactured using additive manufacturing, to accurately replicate the complex surface topography and design features. To validate the design, the target patient anatomy was replicated using additive manufacturing and a 'mock' surgery was performed to assess the device performance. We found our design allowed for efficient placement and use during the mock surgery, confirming the potential of the devised process as a robust methodology for clinical implementation

Design optimisation of a thermoplastic splint

Following partial hand amputation, a post-surgery orthosis is required to hold the remaining ligaments and appendages of the patient in a fixed position to aid recovery. This type of orthosis is traditionally handmade and fabricated using laborious and qualitative techniques, which would benefit from the enhancements offered by modern 3D technologies. This study investigated the use of optical laser scanning, Computer Aided Design (CAD) and Material Extrusion (ME) additive manufacturing to manufacture a polymeric splint for use in post-surgical hand amputation. To examine the efficacy of our techniques, we take an existing splint from a patient and use this as the template data for production. We found this approach to be a highly effective means of rapidly reproducing the major surface contours of the orthosis while allowing for the introduction of advanced design features for improved aesthetics, alongside reduced material consumption. Our demonstrated techniques resulted in a more lightweight and lower cost device, while the design and manufacturing elements afford greater flexibility for orthosis customisation. Ultimately, this approach provides an optimized and complete methodology for orthosis production

Ecoprinting: investigating the use of 100% recycled acrylonitrile butadiene styrene (ABS) for additive manufacturing

Many commonly found polymers have the potential to be recycled, such as Acrylonitrile Butadiene Styrene (ABS), a prevalent 3D printing material. In this study we examine the potential of using 100% recycled ABS to form filaments for use in Fused Deposition Modelling (FDM) 3D printing. We then characterise the resulting changes in the printing quality and mechanical properties, over a single recycling cycle. We found that ABS can undergo recycling and reforming into consistent printer filaments without the addition of virgin material. However, notable changes in polymer characteristics were observed, reflected by degradation in mechanical properties during tensile tests and a decrease in the polymer melt flow, which required reduced raster speed to achieve repeatable prints. Despite these limitations, we demonstrate that recycling and reprinting is possible with acceptable loss of material integrity, and could provide unique opportunities for sustainable use of waste ABS using 3D printing technology

EcoPrinting: investigation of solar powered plastic recycling and additive manufacturing for enhanced waste management and sustainable manufacturing

In this article we propose the EcoPrinting technology, which aims at a near zero carbon foot print means of recycling waste polymers into functional, working products. To achieve this goal, we demonstrate a nanogrid device by which solar energy can be stored in a modest sized battery system and use this to power instrumentation for melt extrusion of waste polymers into 3D printer filaments. We then use this filament in a modified 3D printer system to manufacture functional humanitarian aid components such as water seals and pipe connectors. We investigate the feasibility of the EcoPrinting principal using ABS and HDPE plastics, while evaluating and optimizing enabling device energy consumption and manufacturing performance. We conclude that the EcoPrinting principal is possible and functional devices can be manufactured with mechanical integrity equivalent to commercially available components. We finally demonstrate that EcoPrinting can be used as a tool for humanitarian use, realizing a manufacturing paradigm that is self-sufficient and potentially capable of addressing challenges of plastic proliferation in developing nations

The recycling of E-Waste ABS plastics by melt extrusion and 3D printing using solar powered devices as a transformative tool for humanitarian aid

This study demonstrates the EcoPrinting principal, which makes use of renewable energy to realise a low carbon footprint means of recycling waste plastics into feedstock for Fused Filament Fabrication (FFF) 3D printing. We present our work to date to encapsulate this principal in a singular device, which comprises a nanogrid solar/battery storage unit, a custom made filament extrusion device and modified FFF 3D printer system. We demonstrate that our system is capable of reforming ABS plastics found in electronic waste and converting these into functional items through a melt extrusion and additive manufacturing process. We successfully demonstrate the efficacy of the system to operate using solar derived energy and using the resulting filament to 3D print functional pipe connector components. We conclude Ecoprinting holds considerable potential as a sustainable means of converting waste plastics into functional components. Finally, the portable and self-sufficient nature of the system, Ecoprinting could feasibly could be applied as a cost effective aid solution for vulnerable communities in low socio-economic environments

A lab-on-a-chip that takes the chip out of the lab

A microfluidic system achieves miniaturization without the need for extra equipment, bringing chip-based devices closer to mainstream commercial reality, with a framework that could be widely applied to diagnostics.</p

3D printing of passive microfluidic flow mixers using Triply Period Minimal Surface microlattice structures

Microfluidics are miniaturised devices useful for precision fluid handling phases when conducting a range of chemical reactions or biological processes. Such devices operate at micrometre length scales, where laminar flow dominates and so interactions are limited to diffusion between the flowing liquid interfaces unless flow is made turbulent to induce mixing. Passive mixers are desirable for this task as they comprise geometrical features which can be incorporated during the fabrication of such devices. Designs largely remain planar due to traditional microfluidic manufacturing being conducted with 2.5D fabrication processes. Additive Manufacturing now allows for passive mixers to now be realised in true 3D but have seen limited investigation. This study explores the efficacy of several miniaturised Triply Period Minimal Surface micro-lattice structures, formed within microfluidic channels as turbulence inducing structures for increased mixing. We explore several lattice designs and report on their efficacy for mixing reactions conducted during continuous flow conditions.</p

Digital design and fabrication of controlled porosity, personalized lower limb AFO splints

We present the preliminary phases of developing a custom lower limb splint concept which considers both design and mechanical elements of the final device. We present an approach to verify the flexural properties of the device through the systematic measurement of flexural stress of 3D printed samples and how this evolves based upon increased porosity. Our initial results demonstrate we can effectively predict the stiffness characteristics of a 3D printed splint concept and apply this to inform the design choices

Lab-on-a-chip based immunosensor principles and technologies for the detection of cardiac biomarkers: a review

This review examines the current state of the art lab-on-a-chip and microfluidic based biosensor technologies used in the detection of cardiac biomarkers. The determination and quantification of blood based, cardiac biomarkers are crucial in the triage and management of a range of cardiac related conditions, where time delay has a major impact on short and longer-term outcomes of a patient. The design and manufacturing of biomarker detection systems are multi-disciplinary in nature and require researchers to have knowledge of both life sciences and engineering for the full potential of this field to be realised. This review will therefore provide a comprehensive overview of chip based immunosensing technology as applied to cardiac biomarker detection, while discussing the potential suitability and limitations of each configuration for incorporation within a clinical diagnostics device suitable for point-of-care applications