https://www.um.edu.mt/library/oar/handle/123456789/22536 2026-04-04T20:30:49Z 2026-04-04T20:30:49Z https://www.um.edu.mt/library/oar/handle/123456789/145215 2026-03-27T11:18:37Z 2023-01-01T00:00:00Z

Title: Foot trajectory estimation methods using inertial sensors and multisegment modelling approaches for kinematic gait analysis Abstract: During the last two decades, considerable progress has been made in the use of foot mounted inertial sensors and other auxiliary sensors such as magnetometers, laser range-finder sensors, ultrasonic sensors and cameras for the monitoring of a person’s locomotion. Although these sensors still give a lower accuracy compared to optical motion capture systems, their compactness and reduced cost have made them more convenient for the purpose of estimation of kinematic gait parameters in both laboratory conditions and during daily activities. Most of the wearable setups used in the literature consider the foot, from the heel to the toes, as one rigid body represented by a single-segment foot model. Very few studies have conducted kinematic gait analysis of multi-segment foot models using multiple inertial measurement units (IMUs). For each of these cases and in contrast to the work in this thesis, methods used in single-segment foot models have simply been adapted to a multi-segment foot model scenario. This thesis presents a novel approach for the estimation of the trajectories of a multi-segment foot model by means of multiple IMUs working as auxiliary sensors for the measurement of the trajectory of each foot segment of interest, i.e. hallux, forefoot, hindfoot, and tibia. Two novel multi-segment methods have been proposed achieving higher accuracy in almost all trajectory directions of all segments as compared to the state-of-the-art methods in literature. The first part of this work presents a literature review of the state-of-the-art methods for kinematic gait analysis employing inertial and auxiliary wearable sensors. In contrast to the existing reviews, a comprehensive approach is presented breaking down each method into three main parts instead of two: (1) zero velocity intervals detection; (2) assumptions and considerations for different sensor types; and (3) pose and trajectory methods. Furthermore, the foot pose and trajectory estimation methods considered for the kinematic gait analysis have been divided into three main categories: (1) de-drifting procedures; (2) Kalman filtering methods; and (3) complementary filtering methods. An analysis of a single-segment foot model has been conducted for the estimation of the foot trajectory and pose employing and evaluating these three state-of-the-art methods using a custom-made wearable device with a single low-cost IMU. The objective of this analysis was to identify the best-performing method for low-cost sensors. The results obtained indicated that a de-drifting procedure may be more appropriate for this type of IMU sensor due to the sensor’s high drift errors. The second part of this work presents two novel approaches involving a multisegment analysis method for the estimation of the trajectories of a foot’s segments using multiple IMUs. Instead of tracking each segment separately, i.e. a separate segment approach, a fusion of all accelerometer measurements using kinematic equations was employed, i.e. a linked-segment approach. To the author’s knowledge, this kind of fusion approach for the improvement of the IMU’s accuracy has never been proposed and tested for such an application. Therefore, a comparative analysis of these two proposed linked-segment approaches with respect to a separate-segment approach took place and validated by means of an optical motion capture system used as a reference. The results obtained show that the novel approaches considerably improve the estimated trajectories of each foot segment. Finally, a wearable system relying on the same multi-segment sensor placement and processing methods was implemented and evaluated by participants in two sessions, being shod and unshod. The vertical displacements of all segments among the two sessions were further evaluated and exhibited a high degree of correlation. This suggests that the proposed linked-segment approach and setup may be useful for use in daily life where the user is typically expected to be shod. Hence, the research work in this thesis presents a review on the state-of-the-art methods using IMUs with or without auxiliary sensors for kinematic gait analysis, and two novel approaches for trajectory estimations of multi-segment foot models able to be used outside a laboratory. Description: M.Phil.(Melit.)

2023-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/144587 2026-03-04T13:21:54Z 2025-01-01T00:00:00Z

Title: Towards the analysis of dynamic medical thermography : a framework for registration, segmentation and component analysis Abstract: Maintaining foot health is vital to overall well-being, especially for individuals with diabetes, who are at an elevated risk of developing lower-limb complications due to neuropathy and poor circulation. These conditions heighten the risk of infections, foot ulcers, and, in severe cases, amputations. Monitoring foot temperature offers a non-invasive and effective means of early detection for such complications. Shifts in temperature can indicate underlying issues: reduced temperatures may point to circulatory disorders such as peripheral arterial disease (PAD), while increased temperatures often suggest inflammation or ulceration, which can quickly worsen if left untreated. The thesis explores the application of dynamic thermal imaging for foot health monitoring. Thermography, a non-contact technique that detects infrared radiation emitted from the skin, was employed to visualise and analyse temperature distribution across the foot. Unlike traditional static imaging, this study utilises video-based thermal data to capture temporal changes in temperature distribution. However, incorporating a temporal dimension introduces additional challenges, notably subject movement during video capture. To address this, the study proposes an automated registration method capable of aligning the foot in dynamic thermal sequences without user intervention. A VoxelMorph-trained SynthMorph network was applied to linearly pre-registered videos, and results demonstrate that the method achieves high registration accuracy. The next stage in the processing pipeline involves isolating the foot region from the background in the thermal data. This was achieved using the Segment Anything Model (SAM), which delivered 100% segmentation success with minimal manual input. The final step involves analysing the temperature dynamics within segmented foot region. Due to the complex interplay of physical and environmental factors influencing thermal data, interpretation can be challenging. To address this, Principal Component Analysis (PCA) was used to decompose the temperature dynamics. The findings show that PCA effectively distinguishes between different underlying processes. Overall, the study demonstrates the viability of dynamic thermal imaging for continuous foot health monitoring and highlights its potential as a preventive healthcare tool. Thermography is shown to be reliable, efficient, and accessible method for tracking foot health, paving the way for automated solutions in preventative care. By providing early warning signals, dynamic thermal imaging may improve patient outcomes, lower healthcare costs, and enhance overall quality of life. Description: Ph.D.(Melit.)

2025-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/100221 2023-08-17T10:06:37Z 2021-01-01T00:00:00Z

Title: An investigation of thermal patterns in guitarists performing a musician-specific exercise programme Abstract: Several musicians suffer from musculoskeletal problems during their career. These injuries are referred to as performance-related musculoskeletal disorders (PRMDs). Through the use of exercise programmes, PRMDs can be prevented. Exercise programmes aid to strengthen musicians’ upper limb and supporting muscles, which correct and improve postural control during performance and thereby prevent PRMDs. In this study, a musician-specific exercise programme was carried out by guitarists, and thermal imaging was used to observe and monitor the effect of this exercise programme. Thermal data was collected from 14 guitarists who played their instrument for at least seven hours a week. Data was gathered from the trapezius, shoulder, upper arm, forearm, wrist, and digits for a period of 20 minutes whilst the guitarists were playing. The participants followed the exercise programme throughout a period of six weeks, after which the process of thermal data collection was performed again. While existing studies that evaluate musicians through thermal imaging mostly observe thermal asymmetries, in this work we also looked at absolute and relative temperature changes over time, both before and after the exercise programme. The results obtained show that one of the main and most consistent effects of the musician-specific exercise programme was the reduction of thermal asymmetries within the shoulder region. This is indicative that the musician-specific exercise might be beneficial to avoid or reduce the effect of PRMDs in guitarists. Description: M.Sc.(Melit.)

2021-01-01T00:00:00Z https://www.um.edu.mt/library/oar/handle/123456789/66971 2021-01-11T14:47:58Z 2020-01-01T00:00:00Z

Title: A portable in-shoe measurement system to acquire dense continuous foot temperature maps Abstract: People suffering from diabetes are at risk of developing ulcerations, which, if left untreated, could also lead to amputation. Monitoring of the foot temperature can help identify ulcerations sites before there are any visible signs on the skin. Various studies have shown that elevated temperatures in the foot may be indicative of ulceration. Over the years there have been numerous devices that were designed for foot temperature monitoring, both for clinical and home use. The technologies used vary from infrared (IR) thermometry, liquid crystal thermography (LCT), IR thermography and a vast range of analogue and digital temperature sensors that were incorporated in different measurement platforms. The aim of this thesis is to design an in-shoe portable system that utilises a high-density sensing array to record temperature data from the foot. Software was designed to visualise the recorded temperature data, representing it in format suitable to both clinical and non-clinical users. Various testing was done to validate the system performance, and eventually carried out trial walks with healthy subjects for the analysis of temperature data. The system was able to record temperatures continuously, with the analysed results in line with findings from previous studies. With the systems currently available for in-shoe temperature monitoring, the device designed in this project enable more in-depth analysis of the temperature variations of the foot within the shoe. Description: M.SC.BIOMED.CYB.

2020-01-01T00:00:00Z