Understanding human skin appearance is a subject of great interest in science, medicine and technology. In medicine, skin appearance is a vital factor in surgical/prosthetic reconstruction, medical make-up/tattooing and disease diagnosis. The production of facial prostheses to replace missing facial structures requires the skills of highly trained anaplastologists to correctly match the shape and colour of the prosthesis to that of the host skin. With the 3D printing of human skin now available the process involved in matching natural and manufactured skin samples has become essential; a robust, accurate and efficient imaging system is required that acquires the relevant skin information and predicts a good match and translates this information through this new and innovative manufacturing process. A major problem with manufactured skin is that the match to the individual's natural skin must hold not only be accurate under a particular ambient illumination but the match needs to be preserved when the individual is moving between different environments, e.g. when the individual moves from office or LED lighting into daylight. To achieve this illumination invariance, the physical properties of the skin need to be taken into account. A further requirement for successful skin reproduction is the development of appearance models. These can be considered as individual "recipes' or 'blueprints" for each skin type and these not only represent inter-personal differences - different ethnic groups and age ranges, but also intra-personal differences - for each individual. Features of the human skin (wrinkles, pores, freckles, spots etc) make human skin as individual as a finger prints and thus, for facial prosthetics applications, skin appearance models also need to be fine-tuned for each individual area. The purpose of this work is to develop a complete spectral-based 3D imaging system which will allow us to additively manufacture soft tissue prosthetics or deliver predictable tattooing techniques that will exactly match the skin colour of a particular individual (Application 1) or have the capability to rapidly manufacture/3D print soft tissue replacements representative of a particular ethnic/age/gender group with a high degree of accuracy (Application 2). In application 1, the input to this 3D imaging system will consist of a 3D colour skin image (of a particular individual) obtained with a 3D camera in conjunction other specific skin characteristics. The skin sample will then be printed using a printer profile that maximises the match between the natural and printed skin across different ambient illuminations. In application 2, the skin manufacturing process will not be fine-tuned for a particular individual, but input to the 3D imaging system will consist of basic information about the age, gender and ethnicity. Representative skin samples (colour; texture; translucency; geometry) for this group will then be loaded from a pre-computed library instead of using the measurements from an individual.

The EPSRC Centre in Innovative Manufacturing in Medical Devices will research and develop advanced methods for functionally stratified design and near patient manufacturing, to enable cost effective matching of device function to the patient needs and surgical environment. This will deliver "the right product, by the right process to the right patient at the right time" to an enhanced standard of reliability and performance. The centre will research and develop: 1) Functionally stratified design systems, which will be initially applied to existing device manufacturing processes and subsequently to the manufacture of scaffolds, developing novel pre-clinical simulation methods, which match implant design to patient function, delivering a cost effective Stratified Approach for Enhanced Reliability (SAFER) 2) Innovative near patient manufacturing processes, enabled by stratified and individualised definitions of patient need, to provide a more cost effective approach to personalised devices. The two flagship challenges will be integrated with the key platform capabilities, across the centre to generate, for the first time, a closed loop design and manufacturing framework for medical devices to deliver enhanced performance and reliability. These innovative design and manufacturing advances will focus in the first instance on class 3 medical devices for musculoskeletal disease, where the cost of device failure and need for throughout life reliability are high. The National Centre will develop, lead and integrate an international network of industrialists, academics, clinicians and regulatory body representatives in order to support the musculoskeletal medical device manufacturing industry to deliver the innovative design and manufacturing challenges and implement the outcomes into manufacturing practice in a global highly regulated market. The Centre will create the research infrastructure, tools and methods, expertise and suitably qualified personnel to support continued innovation and growth of the medical device manufacturing sector in the UK. To do so, the Centre will work across the EPSRC priority research areas "Manufacturing the Future" and "Towards next generation healthcare," drawing upon capabilities and collaborating with existing centres of excellence. The Centre will provide a platform for fundamental innovative device manufacturing research and promote its rapid exploitation by industry through outreach and translation activities and a generic platform for diversification into other technologies. It will grow the UK's research capability in medical device manufacturing research to underpin the development of next generation medical devices and the development of high quality manufacturing processes to provide cost effective, reliable and effective devices. It will be applied to enhanced manufacturing of existing devices such as joint replacements and support manufacture of new products and biomaterial scaffolds. The Centre will operate across five leading academic centres of excellence in the field. The Centre will be led by Leeds University (Fisher, Williams, Ingham, Wilcox, Jennings and Redmond) and will be supported by collaboration from Newcastle (Dalgarno and McKaskie), Nottingham (Grant, Ahmed and Warrior), Sheffield (Hatton) and Bradford (Coates). The Centre will work closely with major manufacturers and users including surgeons who see at first hand the challenges of patient and surgical variation. The Centre will provide a platform for developing fundamental medical device manufacturing science and promote its rapid exploitation by industry.