Alan Holloway

Registration of low molecular weight environmental toxins with total internal reflection ellipsometry

A very sensitive optical method of total internal reflection ellipsometry (TIRE) in conjunction with an immune assay approach were exploited for the registration of low molecular weight environmental toxins, such as simazine, atrazine and T2 mycotoxin in a wide range of concentrations down to 0.1 ng/ml. QCM impedance measurements provided additional information on the mechanism of T2 binding.

Medical Devices for Measuring Respiratory Rate in Children: a Review

Respiratory rate is an important vital sign used for diagnosing illnesses in children as well as prioritising patient care. All children presenting acutely to hospital should have a respiratory rate measured as part of their initial and ongoing assessment. However measuring the respiratory rate remains a subjective assessment and in children can be liable to measurement error especially if the child is uncooperative. Devices to measure respiratory rate exist but many provide only an estimate of respiratory rate due to the associated methodological complexities. Some devices are used within the intensive care, post-operative or more specialised investigatory settings none however have made their way into the everyday clinical setting. A non-contact device may be better tolerated in children and not cause undue stress distorting the measurement. Further validation and adaption to the acute clinical setting is needed before such devices can supersede current methods.

Discriminative sensing of volatile organic solvents. Comparative analysis using different QCM techniques

Several quartz crystal microbalance (QCM) sensing techniques have been applied for the selective detection of volatile organic solvents in the pre-explosive vapour concentration range. Through the use of sensor arrays and QCM dissipation measurements, reliable detection and discrimination is made possible.

Mycotoxin Biosensor Based on Optical Planar Waveguide

The research aim of this work is to develop a simple and highly sensitive optical biosensor for detection of mycotoxins. This sensor is built on a planar waveguide operating on the polarization interferometry principle, i.e., detecting a phase shift between p- and s-components of polarized light developed during the binding of analyte molecules. The operation of the proposed sensor is similar to that of a Mach–Zehnder interferometer, while its design is much simpler and it does not require splitting the waveguide into two arms. The refractive index sensitivity of the polarization interferometer sensor was in the range of 5200 radians per refractive index unit (RIU). Several tests were conducted to detect ochratoxin A (OTA) at different concentrations in direct immunoassay with specific antibodies immobilized in the sensing window. The lowest concentration of OTA of 0.01 ng/mL caused a phase shift of nearly one period. The results obtained prove high sensitivity of the sensors, which are capable of detecting even lower concentrations of mycotoxins at the ppt (part-per-trillion) level.

Investigation of Zinc phthalocyanine films for QCM sensing applications

A Quartz Crystal Microbalance (QCM) with 1 0 MHz fundamental resonance was used as the sensing element(s) to monitor changes in the properties of Zinc Phthalocyanine (ZnPc) films caused by adsorption of different types of selected organic vapour, such as hexane and benzene. The experimental admittance spectra of (QCM) around resonance were fitted to an equivalent circuit model (BVD circuit) and parameters relating to film thickness and viscosity were extracted. LabVIEW software was used to control the experimental setup and curve fitting. (ZnPc) films with a range of different substitutes were studied. Additionally, characterization of the film properties has been carried out using parameters obtained from QCM measurements in conjunction with suitable data analysis and modeling techniques. Validation of the film properties has been established (thickness and structure) using complementary existing methods such as AFM and Ellipsometry.

Development of an Intelligent Robotic Rein for Haptic Control and Interaction with Mobile Machines

The rescue services face numerous challenges when entering and exploring dangerous environments in low or no visibility conditions and often without meaningful auditory and visual feedback. In such situations, rescue-personnel may have to rely solely on their own immediate haptic feedback in order to make their way in and out of a burning building by running their hands along the wall as a means of navigation. Consequently, the development of technology and machinery (robot) to support exploration and aid navigation would provide a significant benefit to the search and rescue operation; enhancing the capabilities of the fire and rescue personal and increasing their ability to exit safely [1]. A brief review and analysis of the previous published literature on exploring environments in low or no visibility conditions where haptic feedback has been utilized is provided and the design of a new intelligent haptic rein is proposed.