A Novel Microwave Sensor to Detect Specific Biomarkers in Human Cerebrospinal Fluid and Their Relationship to Cellular Ischemia During Thoracoabdominal Aortic Aneurysm Repair

Thoraco-abdominal aneurysms (TAAA) represents a particularly lethal vascular disease that without surgical repair carries a dismal prognosis. However, there is an inherent risk from surgical repair of spinal cord ischaemia that can result in paraplegia. One method of reducing this risk is cerebrospinal fluid (CSF) drainage. We believe that the CSF contains clinically significant biomarkers that can indicate impending spinal cord ischaemia. This work therefore presents a novel measurement method for proteins, namely albumin, as a precursor to further work in this area. The work uses an interdigitated electrode (IDE) sensor and shows that it is capable of detecting various concentrations of albumin (from 0 to 100 g/L) with a high degree of repeatability at 200 MHz (R2 = 0.991) and 4 GHz (R2 = 0.975)

State-of-the-Art Methods for Skeletal Muscle Glycogen Analysis in Athletes - The Need for Novel Non-Invasive Techniques

Muscle glycogen levels have a profound impact on an athlete’s sporting performance, thus measurement is vital. Carbohydrate manipulation is a fundamental component in an athlete’s lifestyle and is a critical part of elite performance, since it can provide necessary training adaptations. This paper provides a critical review of the current invasive and non-invasive methods for measuring skeletal muscle glycogen levels. These include, the gold standard muscle biopsy, histochemical analysis, magnetic resonance spectroscopy and musculoskeletal high frequency ultrasound, as well as pursuing future application of electromagnetic sensors in the pursue of portable non-invasive quantification of muscle glycogen. This paper will be of interest to researchers who wish to understand the current and most appropriate techniques in measuring skeletal muscle glycogen and to seek understanding in the need for development in equipment which can be used in, e.g., elite sporting competition and improve physiological training adaptations to carbohydrate manipulation

Characterization of alar ligament on 3.0T MRI: a cross-sectional study in IIUM Medical Centre, Kuantan

INTRODUCTION: The main purpose of the study is to compare the normal anatomy of alar ligament on MRI between male and female. The specific objectives are to assess the prevalence of alar ligament visualized on MRI, to describe its characteristics in term of its course, shape and signal homogeneity and to find differences in alar ligament signal intensity between male and female. This study also aims to determine the association between the heights of respondents with alar ligament signal intensity and dimensions. MATERIALS & METHODS: 50 healthy volunteers were studied on 3.0T MR scanner Siemens Magnetom Spectra using 2-mm proton density, T2 and fat-suppression sequences. Alar ligament is depicted in 3 planes and the visualization and variability of the ligament courses, shapes and signal intensity characteristics were determined. The alar ligament dimensions were also measured. RESULTS: Alar ligament was best depicted in coronal plane, followed by sagittal and axial planes. The orientations were laterally ascending in most of the subjects (60%), predominantly oval in shaped (54%) and 67% showed inhomogenous signal. No significant difference of alar ligament signal intensity between male and female respondents. No significant association was found between the heights of the respondents with alar ligament signal intensity and dimensions. CONCLUSION: Employing a 3.0T MR scanner, the alar ligament is best portrayed on coronal plane, followed by sagittal and axial planes. However, tremendous variability of alar ligament as depicted in our data shows that caution needs to be exercised when evaluating alar ligament, especially during circumstances of injury

Case series of breast fillers and how things may go wrong: radiology point of view

INTRODUCTION: Breast augmentation is a procedure opted by women to overcome sagging breast due to breastfeeding or aging as well as small breast size. Recent years have shown the emergence of a variety of injectable materials on market as breast fillers. These injectable breast fillers have swiftly gained popularity among women, considering the minimal invasiveness of the procedure, nullifying the need for terrifying surgery. Little do they know that the procedure may pose detrimental complications, while visualization of breast parenchyma infiltrated by these fillers is also deemed substandard; posing diagnostic challenges. We present a case series of three patients with prior history of hyaluronic acid and collagen breast injections. REPORT: The first patient is a 37-year-old lady who presented to casualty with worsening shortness of breath, non-productive cough, central chest pain; associated with fever and chills for 2-weeks duration. The second patient is a 34-year-old lady who complained of cough, fever and haemoptysis; associated with shortness of breath for 1-week duration. CT in these cases revealed non thrombotic wedge-shaped peripheral air-space densities. The third patient is a 37‐year‐old female with right breast pain, swelling and redness for 2- weeks duration. Previous collagen breast injection performed 1 year ago had impeded sonographic visualization of the breast parenchyma. MRI breasts showed multiple non- enhancing round and oval shaped lesions exhibiting fat intensity. CONCLUSION: Radiologists should be familiar with the potential risks and hazards as well as limitations of imaging posed by breast fillers such that MRI is required as problem-solving tool

Electromagnetic Wearable Sensors: A Solution to Non-Invasive Real-Time Monitoring of Biological Markers during Exercise

Wearable sensing technology enables greater insights into the performance and health status of athletes during training and competition, which are currently unattainable through traditional laboratory-based techniques. The process of collecting accurate data from complex metabolic parameters usually requires the use of specialised equipment and methods that are often expensive and invasive. This research proposes the novel use of a purpose-built electromagnetic (EM) sensor to non-invasively detect biological markers in humans during exercise. Three parameters were selected for investigation: sweat sodium, blood lactate, and skeletal muscle glycogen. Each of these parameters were selected based on their significance to athletic performance monitoring, as well as their current methods of analysis being impractical for real-time monitoring during exercise. Four human studies and two in-vitro sample-based studies were conducted, accumulating in 140 sweat samples, 523 blood lactate samples, and 21 glycogen samples, collected from a combined total of 71 participants, 56 males, and 15 females. The research presented within this thesis demonstrated that a hairpin EM sensor operating at microwave frequencies could detect and measure changes in sodium concentration within human sweat samples at 1.6 GHz (R2 = 0.862). Further sensor development is required for on-subject monitoring of sweat sodium during exercise (R2 = 0.149), findings suggest this was a result of the microwave sensor’s design, rather than sensing capabilities. Additionally, the sensor was shown to measure blood lactate concentration in untrained participants at 3.4-3.6 GHz (R2 = 0.78), and within endurance-trained participants at 3.2-3.8 GHz (R2 = 0.757). Furthermore, results showed that the sensor could detect changes in glycogen sample concentration at 2.11 GHz (R2 = 0.87) and monitor skeletal muscle glycogen in humans when concentrations were grouped into exercise specific ranges at 2.0-2.25 GHz (R2 = 0.91). This research presents an accurate, cost-effective, and efficient method of detecting biological markers non-invasively and continuously during exercise. With future research and development, a single microwave sensor could ultimately lead to improvements in human performance monitoring, enabling individualised and real-time fuelling strategies during training and competition. Further assessment of this technology is needed within a real-world setting to understand if this remains a feasible solution outside of a controlled environment

DETERMINING THE QUALITY OF PASTEURISED AND HOMOGENISED COW MILK USING MICROWAVE SENSORS

More than 6 billion people worldwide consume milk and milk products and this number is rapidly growing every year (FAO, 2015a), there are numerous occurrences where the milk quality was below acceptable standards causing severe health hazards among consumers including young children. The aim of this research work is to design and develop a novel, microwave spectroscopy, approach for determination of overall quality of milk. In particular, this quality determination of milk products was achieved by identification of deterioration or spoilage of milk over time, classification of the milk product based on composition (e.g. fat content), in addition to the contamination (e.g. adulteration due to presence of detergents, urea). An extensive literature review was carried out to establish the scope of the PhD work and in order to achieve the objectives. Current advancements were studied along with the traditional methods of milk quality testing to identify the key areas where further development can take place to enable the quality control of milk products outside the laboratory premises. This work addresses the drawbacks in currently employed methodologies and attempts to overcome or minimize their overall limiting effect. The application of this sensor system is aimed within the milk supply-chain hierarchy after the production at dairy plants and before sale to allow easy and real-time quality testing. The dielectric property tests were conducted to produce unique spectral signatures for three mainly consumed categories of fresh milk; whole milk, semi-skimmed milk and skimmed milk bought from a supermarket over a period of a week, which served to build a reference database. Based on these spectral signatures for the three categories of milk, a planar, microwave resonator sensor acting as a fluidic sensor was designed, simulated and fabricated to determine spoilage, classification of milk and identify presence of contamination. This work has achieved distinct results to verify the statement, followed by validation, to serve as a platform for the establishment of a laboratory based prototype model to test overall quality of Milk products, with coefficient of determination R2 ≥ 0.95 in all experimental measurements

Non-invasive electromagnetic wave sensor for flow measurement and biphase application

Multiphase flow measurement is important in chemical processing, water treatment and oil & gas industry. The multiphase flow sensor proposed in this research utilizes the resonant frequencies that occur inside a cavity and the differences in the permittivity of the measures phases. By measuring this response over the range of discrete frequencies the sample can be characterised. Polar material like water has relatively high permittivity (ε_r= 81), while non-polar material such as oil and gas have low permittivity value (ε_r= 2.2-2.5) and (ε_r= 1) respectively. Hence, a small change in the water fraction may result in a comparatively large frequency shift. In this research, the electromagnetic cylindrical cavity sensor system successfully demonstrated its capability to analyze various fractions of water-gas mixture. The results were consistent in the case of both the static and dynamic flow. The statistical analysis of the captured data showed a linear relationship of the amplitude data with the change in the water fractions. It was also found that the technique was independent of the temperature change. The system was able to successfully detect the stratified, wavy, elongated bubbles and homogeneous flow regimes. The electromagnetic rectangular cavity sensor system is introduced to pick up the tiny shifts in the permittivity when the low permittivity material is used or temperature changes. The microwave sensor system is able to detect water-air fraction, water-oil fraction, oil-air fraction and water temperature. The novel solution of the combination of both cylindrical and rectangular sensor system demonstrates the ability to detect both high and low permittivity changes. These dual-cavity sensor cavity systems have been able to detect water level, flow regime and temperature in the pipe. It also demonstrates that microwave sensors based on the principle of changing permittivity can replace conventional measurement techniques