Tracheal intubation: improving first pass success with smart material solutions

Airway management and intubation procedures continue to challenge anaesthetists. With current equipment not always providing an optimum solution, this can lead to potential serious complications if an airway is not secured quickly. Improvements in airway devices need to be discussed, designed, tested, and implemented. The implementation of the appropriate smart technologies and materials present an opportunity to resolve key issues with bougie-guided intubation. It is suggested that the development of a novel steerable bougie could improve current tracheal intubation practice. This proposition is grounded on using the appropriate research and design development strategies combined with a structured methodological approach

Performance analysis for difficult airway equipment: standardising for success

Equipment design and selection can contribute to the success or failure of difficult airway management. However, evaluative systems for providing the relative performance data for bougie introducers to help inform these choices do not exist outside of bespoke studies. This paper discusses the design development of an innovative tip pressure and shape retention testing system. Working with a design activity model, a set of stringent criteria to inform the manufacture of the testing systems were produced. Once implemented, this testing method can inform future equipment selection to improve procedure success rates and thereby reduce patient complications

Electrical capability of 3D printed unpoled polyvinylidene fluoride (PVDF)/thermoplastic polyurethane (TPU) sensors combined with carbon black and barium titanate

The development of three-dimensional (3D) printed sensors attracts high interest from the smart electronic industry owing to the significant geometric freedom allowed by the printing process and the potential for bespoke composite feedstocks being imbued with specific material properties. In particular, feedstock for material extrusion (MEX) additive manufacturing by fused filament fabrication can be provided with piezoelectricity and electrical conductivity. However, piezoelectricity often requires electrical poling for activation. In this study, a candidate material containing thermoplastic polyurethane (TPU) and carbon black (CB) with conductive and flexible properties is incorporated with piezoelectric elements like polyvinylidene fluoride (PVDF) and barium titanate (BaTiO3) to assess its suitability for sensor applications without electrical poling. Texturing the surface of BaTiO3 particles and adding tetraphenylphosphonium chloride (TPPC) to the composite are evaluated as non-poling treatments to improve the sensor response. It was found that TPU and PVDF produced segregated domain structures within the printed sensors that aligned along the printing direction. Due to the effect of this preferential orientation combined with the presence of raster-raster interfaces, printed sensors exhibited significant electrical anisotropy registering greater electrical waveforms when the electrodes aligned parallel to the raster direction. An improvement of current baseline from 0.4 μA to 12 μA in the parallel direction was observed in sensors functionalised with both treatments. Similarly, when the waveform responses were measured under a standardised impact force, current amplitudes in both orientations registered a twofold increase for any impact force when both treatments were applied to the feedstock material. The results achieved within this study elucidate how composite formulations can enhance the sensor response prior to conducting electrical poling

Utilising object tracking for the performance analysis of difficult airway equipment - a Shape Retention Testing System (SRTS)

Failure to secure the airway on induction of anaesthesia can result in death and disability. Current equipment does not always provide an optimum solution. Most anaesthetists consider bougies essential equipment for safe anaesthesia. Evaluative systems providing accurate objective data assessing bougie introducer performance data do not exist. The Shape Retention Testing System (SRTS) utilises the Intel® RealSenseTM SR300 camera to create an accurate and repeatable testing environment. SRTS collected data will allow anaesthetists to compare device performance that will inform purchase and usage decisions of bougies, ensuring optimum benefit for safe practice

Graphene-like nano-sheets/36° LiTaO3 surface acoustic wave hydrogen gas sensor

Presented is the material and gas sensing properties of graphene-like nano-sheets deposited on 36deg YX lithium tantalate (LiTaO3) surface acoustic wave (SAW) transducers. The graphene-like nano-sheets were characterized via scanning electron microscopy (SEM), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). The graphenelike nano-sheet/SAW sensors were exposed to different concentrations of hydrogen (H2) gas in a synthetic air at room temperature. The developed sensors exhibit good sensitivity towards low concentrations of H2 in ambient conditions, as well as excellent dynamic performance towards H2 at room temperature

Finite element analysis of titanium alloy-graphene based mandible plate

Titanium alloy based maxillofacial plates and implants are widely used in fracture treatment and reconstructions. Filler materials Graphene Nanoplatlets(GNPs) were used in a Titanium alloy maxillofacial plate and a Finite Element Model (FEM) was designed to reconstruct a fractured human mandible. Both 50N and 500N bite forces were applied on the mandible and stress distribution using Von mises failure theory across the plate sections was analyzed. A pure plate was critically stressed at a section near the mandible fracture region for a Von mises stress of nearly 27.5GPa while this stress reduced by nearly 10–22% with the presence of minor composition of GNPs in the plate. GNPs orientation in parallel (21.1 GPa) to the plate axis were more effective in comparison to other orientations(90°, 45° and 135°) and the location variation of these GNPs along the plate had no significant effect on the stress distribution. The fatigue analyses showed that, under these stresses and forces the plate with GNP was able to endure for nearly 7000 days, while the pure Titanium plate could fail by fatigue in approximately 70 days. Hence, presence of minor compositions of GNPs could enhance endurance life of the Titanium plate by reducing stress concentrations at critical sections of the plate

Patient-maintained propofol sedation: the anaesthetists' point of view

Many operations within the UK do not require general anaesthesia, and are instead carried out under sedation. A doctor normally provides this, and as the patient is not in control, they may be either under or over-sedated due to a misjudgement of patient anxiety. One solution would be to allow the patients to directly control their own sedation level. This paper presents an invention for innovation (i4i) project developing such a Patient Maintained Propofol Sedation Device (PMPSD). Due to the health risks associated with under and over-sedation, the anaesthetists' interface takes on an added importance to ensure they can oversee the process and intervene when needed. Through the project, a unique opportunity has arisen where anaesthetists have been involved throughout the interface design process, contributing to the development and testing of a prototype. We present this prototype, highlight its key features and how it differs from existing sedation pump interface systems. As the project continues, the interface will be used as part of a clinical trial at Nottingham University Hospitals NHS Trust involving 80 orthopaedic patients throughout the rest of 2018 and into 2019