This paper is based on work from the Global Research, Innovation, and Education on Assistive Technology (GREAT) Summit that was coordinated by WHO's Global Cooperation on Assistive Technology (GATE). The purpose of this paper is to describe the needs and opportunities embedded in the assistive product lifecycle as well as issues relating to the various stages of assistive product mobilization worldwide. The paper discusses assistive technology product terminology and the dangers of focusing on products outside the context and rolling out products without a plan. Additionally, the paper reviews concepts and issues around technology transfer, particularly in relation to meeting global needs and among countries with limited resources. Several opportunities are highlighted including technology advancement and the world nearing a state of readiness through a developing capacity of nations across the world to successfully adopt and support the assistive technology products and applications. The paper is optimistic about the future of assistive technology products reaching the people that can use it the most and the excitement across large and small nations in increasing their own capacities for implementing assistive technology. This is expressed as hope in future students as they innovate and in modern engineering that will enable assistive technology to pervade all corners of current and potential marketplaces. Importantly, the paper poses numerous topics where discussions are just superficially opened. The hope is that a set of sequels will follow to continue this critical dialog. Implications for Rehabilitation Successful assistive technology product interventions are complex and include much more than the simple selection of the right product. Assistive technology product use is highly context sensitive in terms of an individual user's environment. The development of assistive technology products is tricky as it must be contextually sensitive to the development environment and market as well. As a field we have much to study and develop around assistive technology product interventions from a global perspective.

A normal coordinate analysis on chlorambucil and thioguanine has been carried out with a set of symmetry coordinates following Wilson's F -G matrix method. The potential constants evaluated for these molecules are found to be in good agreement with literature values thereby confirming the vibrational assignments. To check whether the chosen set of vibrational frequencies contribute maximum to the potential energy associated with the normal coordinates of the molecule, the potential energy distribution has been evaluated.

The FTIR and FT Raman spectra of dacarbazine were recorded in the regions 4000-400 and 3500-100 cm -1 , respectively. The optimized geometry, wavenumber, polarizability and several thermodynamic properties of dacarbazine were studied using ab initio Hartree-Fock, MP2 and DFT methods. A complete vibrational assignment aided by the theoretical harmonic wavenumber analysis was proposed. The calculated harmonic vibrational frequencies were compared with experimental FTIR and FT Raman spectra. Based on the comparison between calculated and experimental results and the comparison with related molecules, assignments of fundamental vibrational modes were made. The X-ray geometry and experimental frequencies were compared with the results of theoretical calculations.

This paper applies a robotics-inspired approach to derive a low-dimensional forward-dynamic hybrid model of human walking in the sagittal plane. The low-dimensional model is derived as a subdynamic of a higher-dimensional anthropomorphic hybrid model. The hybrid model is composed of models for single support (SS) and double support (DS), with the transition from SS to DS modeled by a rigid impact to account for the impact at heel-contact. The transition from DS to SS occurs in a continuous manner. Existing gait data are used to specify, via parametrization, the low-dimensional model that is developed. The primary result is a one-degree-of-freedom model that is an exact subdynamic of the higher-dimensional anthropomorphic model and describes the dynamics of walking. The stability properties of the model are evaluated using the method of Poincare. The low-dimensional model is validated using the measured human gait data. The validation demonstrates the observed stability of the measured gait.

The methodology can be used for better knee selection and design of more customized knee geometries. Clinical relevance The method provides a tool to aid in the selection and design of polycentric knees for transfemoral prostheses.

Introduction A new passive polycentric knee called IITM polycentric knee (IPK), where IITM stands for the authors' institution, namely, Indian Institute of Technology Madras, was designed to provide better functionality at a reduced cost. The design of the knee was based on stance phase stability criteria and toe clearance during the swing phase for users in developing countries to handle uneven terrain. The present study features a simulation-based dynamic analysis of a passive single-axis knee (SAK) and IPK to understand the swing phase behavior of the IPK with respect to SAK. This study aims at understanding the advantages and disadvantages of the IPK against a passive SAK to improve its design criteria and enable further development to provide better functionality to the existing passive SAK users. Methods Lower-limb models of a normal leg and prosthetic legs with SAK and IPK were created, their swing phases were simulated, and gait parameters were analyzed. The passive knees in the present study have only frictional damping and no active knee moments, implying the requirement of compensatory strategies for forward progression of the swinging leg. The required frictional damping at the knee joint to obtain near-normal knee motion and the compensations required while using the SAK and IPK were obtained by simulation. The lower-limb dynamics obtained from the simulations was analyzed to understand the performance of the SAK and IPK during swing. Results This study shows that the IPK is superior to an SAK in terms of achieving knee extension in preparation for stance, even without an extension assist and with lower hip effort. The peak hip power during swing with the IPK was 58.7% less than with the SAK. A negative heel clearance was found in terminal swing with the IPK, which demands a compensatory strategy for foot clearance during the swing and shows the necessity for inclusion of a heel clearance parameter in the design of polycentric knees. Conclusions The present work focuses on the swing behavior comparison of passive single-axis and polycentric knees. The study provides insight into the compensatory strategies required to achieve successful forward progression of the swinging leg with both types of knees. The analysis shows the potential for a well-designed passive polycentric knee to be a cost-effective alternative to achieve near-normal swing during walking.

Semi-active systems using magnetorheological fluids have been realized in many novel devices such as linear dampers, rotary dampers, brakes, and so on. Rotary vane-type magnetorheological damper is one such device that uses magnetorheological fluid as a hydraulic medium and a controllable magnetorheological valve to generate variable resistance. This device, due to its limited angle motion, lends itself to a natural application for prosthetic knee joint. In this article, a bypass rotary vane-type magnetorheological damper suitable for prosthetic knee device is designed. In the proposed design, the rotary vane chamber and the bypass magnetorheological valve are connected using hydraulic cables and ports. The design of rotary cylinder is implemented based on the largest possible dimensions within the envelope of a healthy human knee, while the magnetorheological valve is designed optimally using a multi-objective genetic algorithm optimization. Off-state braking torque, induced on-state braking torque and mass of the valve are selected as three objectives. The torque and angular velocity requirements of the normal human knee are used as design limits. The optimal solution is chosen from the obtained Pareto fronts by prioritizing the objective of weight reduction of magnetorheological valve. The optimal solution is capable of producing a damping torque of 73 Nm at a design speed of 8.4 rpm and current supply of 1.9 A. Potential benefits offered by this design when compared with multi-plate magnetorheological brake are flow mode operation, large clearance gap, and fewer design components, thus reducing the manufacturing complexity.

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