Objective. In this study it was investigated whether an artificial neural network can be used to determine the horizontal, fore-aft component of the ground reaction force from insole pressure patterns. Design. An artificial neural network was applied to map insole pressures and ground reaction forces. Method. To train an artificial neural network insole pressure patterns and ground reaction force data were simultaneously determined for a wide range of different speeds (0.9-2.3 m s−1) for five subjects. Both intrasubject and intersubject generalizability were evaluated. Results. At the intrasubject level generalizability was good when the speed for which the force was to be predicted was within the range of speeds from which data were used to train the network. Besides in some cases, generalizability to a condition outside the range of training conditions could be demonstrated. At the intersubject level the quality of generalization differed widely over subjects, from poor to good. Conclusions. It was found that an artificial neural network is able to map the relationship between insole pressure patterns and the fore-aft component of the ground reaction force. Relevance Good intrasubject generalization of 'knowledge' obtained by an artificial neural network will allow the assessment of the fore-aft component of ground reaction force in condition that cannot be evaluated with force plates, e.g. activities of daily living or real sport situations. Additionally, intersubject generalization will allow shear-force recordings in subjects that are not able to complete a great number of runs to acquire enough force-plate hits.
Force transmission across the wrist during a grasping maneuver of the hand was simulated for three children with juvenile idiopathic arthritis (JIA) and for one healthy age-matched child. Joint reaction forces were estimated using a series of springs between articulating bones. This method (i.e., rigid body spring modeling) has proven useful for examining loading profiles for normally aligned wrists. A novel method (i.e., sliding rigid body spring modeling) designed specifically for studying joint reaction forces of the malaligned JIA wrist is presented in this paper. Loading profiles across the wrist for the unimpaired child were similar using both spring modeling methods. However, the traditional fixed-end method failed to converge to a solution for one of the JIA subjects indicating the sliding model may be more suitable for investigating loading profiles of the malaligned wrist. The results of this study suggest that a larger proportion of force is transferred through the ulno-carpal joint of the JIA wrist than for healthy subjects, with a less than normal proportion of force transferred through the radio-carpal joint. In addition, the ulnar directed forces along the shear axis defined in this study were greater for all three JIA children compared to values for the healthy child. These observations are what were hypothesized for an individual with JIA of the wrist.
Description of a new hand/palm-held computerized 3D force measuring system. The system is built for interface (direct) measurement of 3D manual contact force with real-time data presentation. Static calibration was performed of the 3D force sensor with variable preloads to study their effect as well of the prototype system adapted for clinical manual examination and treatment. The new system enables, for the first time, recording and presenting of 3D manual contact forces at the patient-practitioner interface. 3D direct manual contact force measures have the potential to give a more complete and differentiated characterization of patient and practitioner forces than 1D forces. Clinical validity of the prototype system will have to be investigated, and for studying specific clinical manual handling techniques, obvious limitations require further development.
In Europe nearly 10% of the population suffers from diabetes and almost 1% from Rheumatoid Arthritis which can lead to serious problems with mobility and active participation, especially in the ageing population. Pedorthists deliver personalised designed and manufactured orthopaedic footwear or insoles for these patients. However, despite their often laborious efforts upfront, the industry has very little means to quantify how successful the fitting and function of a shoe is. They have to rely on subjective, qualitative measures such as client satisfaction and diminishing of complaints. Although valuable, the need for objective quantitative data in this field is growing. Foot plantar pressure and shear forces are considered major indicators of potential foot problems. Devices to measure plantar pressure slowly gain terrain as providers of objective quantitative data to guide orthotic design and manufacturing. For shear forces however, measuring devices are not yet commercial available. Although shear forces are considered as a major contributor to ulcer formation in diabetic feet, their exact role still requires elucidation and quantification. This project aims to develop a prototype of an in-shoe wearable device that measures both shear forces and pressure using state-of-the-art developments in sensor technologies, smart textiles and wireless data transfer. The collaboration of pedorthists’ small and medium-sized enterprises (SME)’s with medical device engineering companies, knowledge institutes,technical universities and universities of applied sciences in this project will bring together the different fields of expertise required to create an innovative device. It is expected that the tool will be beneficial to improve the quality of pedorthists’ services and potentially reduce health insurance costs. Furthermore, it can be used in new shear forces research and open new business potential. However, the eventual aim is to improve patient care and help maintain personal mobility and participation in society.
The ongoing debate over the use of fossil fuels, particularly diesel, in engines due to concerns about global climate change has prompted the exploration of alternative propulsion methods and fuels. Despite various proposed alternatives, diesel engines continue to play a vital role in the global market [1]. This discussion has spurred innovations aimed at enhancing the performance and sustainability of diesel engines, including the utilization of biodiesel mixtures, synthetic fuels, and water-in-diesel emulsions (W/D emulsions) [2-5]. Scientific evidence indicates that the presence of water in water-diesel emulsions can improve engine performance and reduce emissions, such as particulate matter and NOx [6,7]. This performance enhancement is attributed to the phenomenon of micro-explosion, or secondary atomization, caused by the differing boiling points of water and diesel [8]. The rapid temperature increase during fuel injection leads to the explosive vaporization of dispersed water droplets, breaking up the diesel emulsion into smaller droplets and resulting in a shorter combustion time. Various processes, including membrane emulsification, ultrasound emulsification, and high shear stirring, are employed to create these emulsions, often necessitating the use of surfactants for stability [9]. This research proposes a two-fold approach: firstly, the use of Electrohydrodynamic Atomization (EHDA, or electrospray) to create stable water-diesel emulsions. Secondly, the employment of magnetic fields in treating both diesel and water-diesel emulsions. EHDA is already used in several applications, such as drug encapsulation, bioencapsulation, thin film coatings and is also known for its ability to form stable emulsions. [10-13]. For the second approach, it has been shown that nanobubbles can be formed [17] and stabilized due to the electric charging action of magnetic fields [18]. We hypothesize that the charged bubbles can further stabilize the diesel-water emulsion and also enhance the explosive evaporation due to the additional Coulomb forces in play.
