Cambodia is one of the world's most landmine affected countries with over 64,000 casualties recorded since 1979 and over 25,000 amputees. Added to this there is also a rise in the number of amputations resulting from road traffic accidents. Currently around 10 million people in South East Asia, India and Sri Lanka need but do not have access to prosthetic and orthotic services and there is a deficit of circa 40,000 professionals. This project directly targets end-users (Prosthetists and amputees) in Cambodia with a view to future expansion into the Philippines, Myanmar, Indonesia and Sri Lanka through strategic partnership with Prosthetics and Orthotics NGO Exceed Worldwide and the Exceed Research Network. We have active collaborations with UK (and European) prosthetics manufacturers (Blatchfords, Otto Bock, Össur), NHS prosthetics and rehabilitation services, and the Defence National Rehabilitation Centre Headley Court. Recent developments in medical care have resulted in a surgical preference for through-knee amputation where previously above knee amputation was considered preferable. Through-knee amputations allow the socket for the prosthesis to fit on the stump so that the load through the artificial foot and knee is transmitted directly to the end of the stump; this maintains healthy, normal load through the thigh bone. An above knee amputation does not permit this normal loading; the socket has to transmit the loads all the way to the pelvic bone, partially bypassing the thigh, causing pressure sores, inhibiting the range of motion of the amputated limb, and producing bone fragility in the thigh. Therefore, through-knee amputations result in a reduction in pain, fewer incidences of bone formation within muscle (a highly debilitating complication), the ability to bear significantly higher loads, and maintain bone health. The cost (>£50,000 per device) and maintenance required make modern sockets and powered knee mechanisms designed for through-knee amputees inappropriate for use in low and middle income countries. Current low cost solutions for this provided by the adaptation of Red Cross knee joint prostheses suffer from major limitations such as an inability to be locked in extension, severe compromises on cosmetic appearance resulting in social exclusion, and a very low prosthetic knee joint (due to the long thigh component) producing other functional deficits. In this project we will develop a low-cost through-knee prosthesis the initial concept for which has been developed by the applicants through prior work with partners in Cambodia. This will be developed further to create a pathway to support the translation of future frugal technology projects (projects that are low cost in terms of manufacture and maintenance) and we will populate this frugal technology pathway with a series of follow on prosthetics and orthotics projects for amputees. Finally, we will ensure that there is a route to harness the frugal technology development for low and middle income countries for the benefit of healthcare in the UK. This project will create a community of researchers, engineers and clinicians developing and translating affordable prostheses.

There have been a number of exciting research developments in the field of bio-integrated and neural connected limb prosthetics. However, it has been shown that the range and lifetime of functionality is limited due to failures at both nerve and muscle interfaces, leading to signal loss and mechanical failure, respectively. Our vision is to challenge the mind-set of limb prosthesis being a disparate and mismatched entity to one where it may be truly interactive and integrated with the residual anatomy and physiology. Our envisaged prosthesis will respond to biological feedback via a tissue engineered abiotic/biotic conduit between the artificial prosthetic and remaining biological muscle and nerves. This will provide the natural and full range of communication and feedback with afferent and efferent connections to the neural system with an emphasis on integration and long-term reliability. This will be achieved through exploration and understanding the fundamental engineering and manufacture of bespoke 3D coupling constructs that encourage and facilitate the robust integration and interface with tissue-engineered skeletal muscle and nerves, and their ancillary structures. The researching will entail developing a new manufacturing process, and the associated sciences, through a multidisciplinary team comprising of manufacturing engineering, biological science and chemistry. Considerations for industrial scale-up, good manufacturing practice (GMP) and regulatory requirements are integrated throughout. The work will be conducted in partnership with a world-leading UK prosthetic manufacturing company along with clinical engagement.

Every year, thousands of people lose a lower limb as a result of a range of factors such as circulatory problems, complications of diabetes or trauma. Current lower limb prostheses can be divided into three groups: i) Purely passive mechanical and requiring a significant voluntary control effort; ii) Actively controlled in which the limb performance is measured and parameters altered to improve performance; iii) Actively driven, or powered prostheses using actuators to directly input mechanical work into the limb. The latter devices do not take into consideration the dynamic interaction between the body elements and prostheses. As a result, they require large amounts of energy and have low efficiency. Therefore they are not in harmony and synergy with the human body. Hence, there is a need for a new generation of lower limb prostheses which can mimic the human muscle by combining active and passive modes. The new generation of prostheses should have a plug and play characteristic and the limb would self tune to the current walking situation (level, slopes and stairs) to optimise the system performance to the user. During the walking cycle, the artificial limb will switch between delivering energy to the walking motion to harvesting energy during the swing phase; prolonging battery power and reducing the burden on the batteries. The aim of this project is to design and develop a new smart lower limb prosthesis through a research programme structured around the following activities. 1) Use of body hub sensors to measure gait dynamics in real time; 2) Use of prosthesis integrated sensors interfaced with the human limb to measure reaction loads during prosthesis use; 3) Estimation of user intent and evaluation of the potential for haptic or other forms of feedback from the prosthesis to enhance its usability; 4) Optimisation of energy use through dynamic coupling and energy generation; and 5) Improvements in limb comfort associated with extended periods of wear. The outcome of the research will be a step change towards the use of technology in relation to the human body and mobility considering human-machine dynamic interaction. The research outcomes will address a number of healthcare challenges associated with the restoration of mobility in amputees, and paves the way for a new direction in the design and development of devices to support mobility in an aging population and applications such as the rehabilitation of stroke patients. The world's third largest manufacture of prosthetics is in the UK and this research will boost the advancement of the UK position worldwide by providing enhanced opportunities for commercialisation.

There have been a number of exciting research developments in the field of bio-integrated and neural connected limb prosthetics. However, it has been shown that the range and lifetime of functionality is limited due to failures at both nerve and muscle interfaces, leading to signal loss and mechanical failure, respectively. Our vision is to challenge the mind-set of limb prosthesis being a disparate and mismatched entity to one where it may be truly interactive and integrated with the residual anatomy and physiology. Our envisaged prosthesis will respond to biological feedback via a tissue engineered abiotic/biotic conduit between the artificial prosthetic and remaining biological muscle and nerves. This will provide the natural and full range of communication and feedback with afferent and efferent connections to the neural system with an emphasis on integration and long-term reliability. This will be achieved through exploration and understanding the fundamental engineering and manufacture of bespoke 3D coupling constructs that encourage and facilitate the robust integration and interface with tissue-engineered skeletal muscle and nerves, and their ancillary structures. The researching will entail developing a new manufacturing process, and the associated sciences, through a multidisciplinary team comprising of manufacturing engineering, biological science and chemistry. Considerations for industrial scale-up, good manufacturing practice (GMP) and regulatory requirements are integrated throughout. The work will be conducted in partnership with a world-leading UK prosthetic manufacturing company along with clinical engagement.

The loss of a limb or limb segment will profoundly affect an individual's internal body representation, which will necessitate biomechanical adaptation to restore function. As sensory feedback from the ankle and plantar surfaces of the feet are known to play a major role in controlling human standing and walking, individuals who have one (or both) of their lower limbs amputated have to learn to use other sensory inputs in order to walk using an artificial device they have only partial awareness of and control over. Understanding the sensorimotor mechanisms used by amputees in adaptive gait involving negotiation of obstacles and descent of steps/stairs, is especially important as such tasks are completed leading with the prosthesis. As well as ensuring the prosthetic foot clears the obstacle/step edge as the limb is swung forwards, the prosthetic limb should also be appropriately positioned at ground contact so that it is loaded optimally. If it is loaded optimally the mechanical function of mechanisms designed to improve the biomechanics of ground contact (e.g. device to attenuate impact forces, device to allow controlled knee-joint flexion) can be taken full advantage of. This highlights that gait safety and gaining full advantage of a prosthesis' mechanical function may both be affected by the level of sensorimotor control an amputee has over their prosthetic limb. Incorporating design features that enhance sensorimotor control, therefore, may be as important as design features which enhance mechanical function. However, because little is known about the sensorimotor mechanisms used by amputees to control their prosthesis, manufacturers are unclear on how to design such features in a prosthesis. Therefore in order to maximise the use of ever smaller advancements in prosthetic technology there is vital need for research on the sensorimotor control mechanisms used by amputees. The proposed research addresses the lack of knowledge in this area.By analysing how amputees are able to negotiate floor-based obstacles and descend steps (leading with their prosthesis) while wearing goggles to prevent them seeing the prosthesis, the proposed study will determine the extent to which control of the prosthetic limb/foot is reliant on vision versus the sense of 'feel' from the prosthetic limb. The degree to which these measures are associated with limb and joint position and movement sense or sense-of-feel from the limb-residuum will also be explored. Finally, as the sense-of-feel from the prosthetic limb is thought to be related to the mechanical loads/pressures on the residuum, the proposed study will explore whether the reliance on using vision to control the prosthetic limb is reduced when using a prosthesis with a self-aligning foot-ankle device that is known to reduce residuum loads when walking over stairs.The insights gained will determine the sensorimotor mechanisms that are critical to gait safety in this population group. Findings will highlight whether resources should be directed at designing prostheses that optimise the sense-of-feel from the prosthesis, rather than solely being directed at optimising their mechanical function as currently is the case. In addition, if lower-limb amputees are found to be more reliant on using vision to control their prosthetic limb when walking over steps and obstacles, this will indicate that visual impairment will have a considerable impact on gait safety in this population group and thus will highlight the importance of regular visual screening in lower-limb amputees. Related to this, if use of a self-aligning foot-ankle prosthesis is found to be less reliant on using visual control, then this will highlight the benefit of using such a device in amputees who are visually impaired.