Biomechanical motion analysis in the clinical environment : the dawn of a new era ?

Philip Rowe looks at biomechanical motion analysis and the work the department of Biomedical engineering at the University of Strathclyde, Glasgow, UK (formerly the Bioengineering Unit), has played a key role in these developments over the last 50 years

Gait and trunk movement patterns of low back pain patients and healthy volunteers during supported and conventional treadmill walking

This study investigates the effects of body weight supported and conventional treadmill walking on gait and trunk motion of asymptomatic people and low back pain (LBP) patients. Forty participants, 19 LBP patients and 21 asymptomatic individuals were recruited. Significant differences were found in gait and trunk kinematic parameters between the two walking conditions, in both participant groups

The Anatomy of an adaptive multimedia presentation system

The use of multimedia presentations within learning environments is described and guidelines for the design of good E-Learning systems are identified. It is argued that a linear sequential presentation of knowledge segments is effective, but that the user is provided with optional links to relevant segments during the presentation. The synchronisation of multiple media is considered and the design of a prototype E-Learning system is discussed. The segmentation of material is then discussed and how the information can be stored in a data repository consider with respect to the requirement of accessing linked segments. Finally, the nature of adaptivity is discussed leading to a discussion of the salient parts of an adaptive multimedia presentation system

Optical Techniques for Fruit Firmness Assessment

This thesis describes the design and development of a new high-speed multispectral imaging (MSI) system compatible with a commercial grading line. The purpose of this system was to carry out spatially resolved spectroscopy to assess fruit firmness. Captured images were analysed using diffusion theory and modified Lorentzian models to extract a sample’s optical properties (absorption and reduced scattering coefficients) and optical parameters respectively. The high-speed MSI system was designed to capture images of fruit using a high-resolution complementary metal–oxide–semiconductor camera, 12.5 mm lens, and discrete lasers operating at 685, 850, and 904 nm. Each laser illuminates a separate fruit, and the camera captures the interacting light with a single frame encompassing all three fruit. Depending on the size of each fruit the spatial resolution with the 12.5 mm lens ranged from 0.15 to 0.22 mm/pixel. Initial measurements were made on 200 ‘Royal Gala’ apples to identify the relationships between the optical properties or parameters and either acoustic or the industry standard penetrometer firmness measurements. Performance of the high speed MSI system was poor compared to the results seen in the literature using alternative spatially resolved spectroscopic systems and other apple varieties. Only weak correlations (R = 0.33) were found between the individual optical measurements and firmness. Unsatisfactory performance from the high-speed system led to the development of a static MSI system to measure stationary fruit and the development of an inverse adding-doubling (IAD) system to provide an independent measurement of the samples optical properties. The purpose of these systems was to help understand the measurement, reduce variability, and give an indication of the upper level of performance possible. The static MSI system featured a number of improvements including the addition of a 980 nm laser, the elimination of an asymmetry caused by laser polarisation, improved temperature control, an electronic shutter system, precise location control of the fruit, and a new 25 mm lens improving spatial resolution (0.057mm/pixel). A second study was carried out using the new MSI and IAD systems on 92 ‘Royal Gala’ apples. Fruit were sliced to expose a flat measurement surface eliminating variation caused by fruit curvature and skin pigments. With these refinements and simplifications the relationships between optical properties or parameters and penetrometer firmness strengthened. As fruit softened and penetrometer firmness fell the reduced scattering coefficient measured by both the IAD and MSI system increased with correlation coefficients ranging from -0.62 to -0.70. The absorption coefficients measured by the two systems showed the expected features related to the absorption of chlorophyll and carotenoid pigments, and water absorption. As the fruit softened chlorophyll absorption decreased as the pigments are broken down and carotenoid absorption increased as new pigments are synthesised. No useful relationships were identified between the optical measurements and acoustic firmness. Multiple linear regression models were formed to predict penetrometer firmness using either the optical properties or modified Lorentzian parameters. The best performing model used a combination of the absorption and scattering coefficients, and had a correlation coefficient of 0.8 and a standard error of 5.87 N

Hands-off and hands-on casting consistency of amputee below knee sockets using magnetic resonance imaging

Residual limb shape capturing (Casting) consistency has a great influence on the quality of socket fit. Magnetic Resonance Imaging was used to establish a reliable reference grid for inter cast and intra cast shape and volume consistency of two common casting methods, Hands-off and Hands-on. Design: Residual limbs were cast for twelve people with a unilateral below knee amputation and scanned twice for each casting concept. Subsequently, all four volume images of each amputee were semi-automatically segmented and registered to a common coordinate system using the tibia and then the shape and volume differences were calculated. Results: The results show that both casting methods have intra cast volume consistency and there is no significant volume difference between the two methods. Inter and intra cast mean volume differences were not clinically significant based on the volume of one sock criteria. Neither the Hands-off nor the Hands-on method resulted in a consistent residual limb shape as the coefficient of variation of shape differences was high. Conclusion: The resultant shape of the residual limb in the Hands-off casting was variable but the differences were not clinically significant. For the Hands-on casting, shape differences were equal to the maximum acceptable limit for a poor socket fit

Falls prevention advice and visual feedback to those at risk of falling : study protocol for a pilot randomized controlled trial

Studies have shown that functional strength and balance exercises can reduce the risk of falling in older people if they are done on a regular basis. However, the repetitive nature of these exercises; combined with the inherent lack of feedback of progress may discourage seniors from exercising in the home, thereby rendering such an intervention ineffective. This study hypothesizes that the use of visual feedback and multimodal games will be more effective in encouraging adherence to home rehabilitation than standard care; thereby promoting independence and improving the quality of life in older adults at risk of falling

Examination of anticipated chemical shift and shape distortion effect on materials commonly used in prosthetic socket fabrication when measured using MRI: a validation study

The quality of lower-limb prosthetic socket fit is influenced by shape and volume consistency during the residual limb shape-capturing process (i.e., casting). Casting can be quantified with magnetic resonance imaging (MRI) technology. However, chemical shift artifact and image distortion may influence the accuracy of MRI when common socket/casting materials are used. We used a purpose-designed rig to examine seven different materials commonly used in socket fabrication during exposure to MRI. The rig incorporated glass marker tubes filled with water doped with 1 g/L copper sulfate (CS) and 9 plastic sample vials (film containers) to hold the specific material specimens. The specimens were scanned 9 times in different configurations. The absolute mean difference of the glass marker tube length was 1.39 mm (2.98%) (minimum = 0.13 mm [0.30%], maximum = 5.47 mm [14.03%], standard deviation = 0.89 mm). The absolute shift for all materials was <1.7 mm. This was less than the measurement tolerance of +/–2.18 mm based on voxel (three-dimensional pixel) dimensions. The results show that MRI is an accurate and repeatable method for dimensional measurement when using matter containing water. Additionally, silicone and plaster of paris plus 1 g/L CS do not show a significant shape distortion nor do they interfere with the MRI image of the residual limb

Vehicle lead-acid battery state-of-charge meter

We describe a state-of-charge, or “residual-capacity” meter for lead-acid batteries that intelligently synthesizes coulometric and terminal-voltage methods in a new algorithm to provide reliable, continuous readout of remaining capacity. Novel electronic circuit design eliminates the need to install a shunt in the vehicle. The meter learns the characteristics of a battery to which it is attached, removing the need for setup, customisation, programming or calibration at time of installation or battery replacement. The meter can thus be installed by unqualified personnel. Initial measurements suggest the design to be robust and accurate

Rules And Institutions

This thesis contains four related but self-contained essays, plus a short introductory chapter. The central theme is the rationality of agents\u27 following rules, as opposed to discretionary action, in contexts where optimal plans under rational expectations are time-inconsistent. The first essay examines the rationality of keeping promises and of trusting that promises will be kept. The second essay argues that social institutions are identical to agents\u27 following, and being believed to follow, rules of action, and uses this perspective to analyse the existence of property rights. The third essay uses the assumption of costly monitoring of worker malfeasance and hence imperfect trust to explain non-compensating wage-differentials between identical workers and equilibrium unemployment. The fourth essay presents a theory of strikes as the consequence of the rules of action followed by firm and worker to enforce a contingent wage contract under imperfectly symmetric information

Requirements for an Adaptive Multimedia Presentation System with Contextual Supplemental Support Media

Investigations into the requirements for a practical adaptive multimedia presentation system have led the writers to propose the use of a video segmentation process that provides contextual supplementary updates produced by users. Supplements consisting of tailored segments are dynamically inserted into previously stored material in response to questions from users. A proposal for the use of this technique is presented in the context of personalisation within a Virtual Learning Environment. During the investigation, a brief survey of advanced adaptive approaches revealed that adaptation may be enhanced by use of manually generated metadata, automated or semi-automated use of metadata by stored context dependent ontology hierarchies that describe the semantics of the learning domain. The use of neural networks or fuzzy logic filtering is a technique for future investigation. A prototype demonstrator is under construction