Ultra-Wideband Communication and Sensor Fusion Platform for the Purpose of Multi-Perspective Localization

Localization is a keystone for a robot to work within its environment and with other robots. There have been many methods used to solve this problem. This paper deals with the use of beacon-based localization to answer the research question: Can ultra-wideband technology be used to effectively localize a robot with sensor fusion? This paper has developed an innovative solution for creating a sensor fusion platform that uses ultra-wideband communication as a localization method to allow an environment to be perceived and inspected in three dimensions from multiple perspectives simultaneously. A series of contributions have been presented, supported by an in-depth literature review regarding topics in this field of knowledge. The proposed method was then designed, built, and tested successfully in two different environments exceeding its required tolerances. The result of the testing and the ideas formulated throughout the paper were discussed and future work outlined on how to build upon this work in potential academic papers and projects.

Graphene FET Sensors for Alzheimer's Disease Protein Biomarker Clusterin Detection

We report on the fabrication and characterisation of graphene field-effect transistor (GFET) biosensors for the detection of Clusterin, a prominent protein biomarker of Alzheimer’s disease (AD). The GFET sensors were fabricated on Si/SiO₂ substrate using photolithographic patterning and metal lift-off techniques with evaporated chromium and sputtered gold contacts. Raman Spectroscopy was performed on the devices to determine the quality of the graphene. The GFETs were annealed to improve their performance before the channels were functionalized by immobilising the graphene surface with linker molecules and anti-Clusterin antibodies. Concentration of linker molecules was also independently verified by absorption spectroscopy using the highly collimated micro-beam light of Diamond B23 beamline. The detection was achieved through the binding reaction between the antibody and varying concentrations of Clusterin antigen from 1 to 100 pg/mL, as well as specificity tests using human chorionic gonadotropin (hCG), a glycoprotein risk biomarker of certain cancers. The GFETs were characterized using direct current (DC) 4-probe electrical resistance (4-PER) measurements, which demonstrated a limit of detection of the biosensors to be ∼ 300 fg/mL (4 fM). Comparison with back-gated Dirac voltage shifts with varying concentration of Clusterin show 4-PER measurements to be more accurate, at present, and point to a requirement for further optimisation of the fabrication processes for our next generation of GFET sensors. Thus, we have successfully fabricated a promising set of GFET biosensors for the detection of Clusterin protein biomarker. The developed GFET biosensors are entirely generic and also have the potential to be applied to a variety of other disease detection applications such as Parkinson’s, cancer, and cardiovascular.

Label-Free Sensors Based on Graphene Field-Effect Transistors for the Detection of Human Chorionic Gonadotropin Cancer Risk Biomarker

We report on the development of label-free chemical vapour deposition (CVD) graphene field effect transistor (GFET) immunosensors for the sensitive detection of Human Chorionic Gonadotropin (hCG), a glycoprotein risk biomarker of certain cancers. The GFET sensors were fabricated on Si/SiO₂ substrate using photolithography with evaporated chromium and sputtered gold contacts. GFET channels were functionalised with a linker molecule to an immobile anti-hCG antibody on the surface of graphene. The binding reaction of the antibody with varying concentration levels of hCG antigen demonstrated the limit of detection of the GFET sensors to be below 1 pg/mL using four-probe electrical measurements. We also show that annealing can significantly improve the carrier transport properties of GFETs and shift the Dirac point (Fermi level) with reduced p-doping in back-gated measurements. The developed GFET biosensors are generic and could find applications in a broad range of medical diagnostics in addition to cancer, such as neurodegenerative (Alzheimer's and Parkinson's ) and cardiovascular disorders.

Unexpected emergency department death: incidence, causes, and relationship to presentation and time in the department

STUDY OBJECTIVE

To determine the incidence and causes of unexpected death in emergency department patients and its relationship to initial ED presentation. To determine if length of ED stay is directly related to unexpected death.

DESIGN

Retrospective chart review of all patients dying in the study ED during a three-year period. Patients receiving CPR on admission or who had "do not resuscitate" orders were classified as expected deaths. Vital signs, level of consciousness, length of time in the ED, and cause of death were recorded for all unexpected deaths.

SETTING

Five hundred sixty-six-bed medical center with an ED volume of 45,000 patients per year.

PARTICIPANTS

Four hundred eleven patients were pronounced dead from 1987 to 1989, and 403 (98%) charts were available.

RESULTS

Fifty-seven (14%) patients met the unexpected death criteria. Abnormal vital signs or altered level of consciousness was observed in 56 (98%) patients on presentation. Medical causes accounted for 42 (74%) of the unexpected deaths. Five (9%) surgical and ten (18%) trauma-related deaths were identified. The yearly incidence of unexpected death was 4.9 (per 10,000 ED visits) in 1987 and 4.1 in both 1988 and 1989. Average length of time in the ED before unexpected death increased during the study period (1987, 91 minutes; 1988, 110 minutes; 1989, 116 minutes).

CONCLUSION

Unexpected ED death was uncommon, usually nontraumatic, and occurred in patients with evidence of significant illness. Although average length of stay in the ED increased, there was no increase in the incidence of unexpected ED death. If lengths of ED stay continue to increase, this situation will require further study.