Optimal Port Placement And Automated Robotic Positioning For Instrumented Laparoscopic Biosensors

OPTIMAL SURGICAL PORT PLACEMENT AND AUTOMATED ROBOTIC POSITIONING FOR RAMAN AND OTHER BIOSENSORS by BRADY KING January 2011 Advisors: Dr. Abhilash Pandya, Dr. Darin Ellis, Dr. Le Yi Wang, and Dr. Greg Auner Major: Computer Engineering Degree: Doctor of Philosophy Medical biosensors can provide new information during minimally invasive and robotic surgical procedures. However, these biosensors have significant physical limitations that make it difficult to find optimal port locations and place them in vivo. This dissertation explores the application of robotics and virtual/augmented reality to biosensors to enable their optimal use in vivo. In the first study, human performance in the task of port placement was evaluated to determine if computer intervention and assistance was needed. Using a virtual surgical environment, we present a number of targets on one or more tissue surfaces. A human factors study was conducted with 20 subjects that analyzed the subject\u27s placement of a port with the goal of scanning as many targets as possible with a biosensor. The study showed performance to be less than optimal with significant degradation in several specific scenarios. In the second study, an automated intelligent port placement system for biosensor use was developed. Patient data was displayed in an environment in which a surgeon could indicate areas of interest. The system utilized biosensor physical limitations and provided the best port location from which the biosensor could reach the targets on a collision-free path. The study showed that it is possible to find an optimal port location for proper biosensor data capture. In the final study, a surgical robot was investigated for potential use in holding and positioning a biosensor in vivo. A full control suite was developed for an AESOP 1000, enabling the positioning of the biosensor without hand manipulation. It was found that the robot lacks the accuracy needed for proper biosensor utilization. Specific causes for the inaccuracies were identified for analysis and consideration in future robotic platforms. Overall, the results show that the application of medical robotics and virtual/augmented reality is able to overcome of the significant physical limitations inherent to biosensor design that currently limit their use in surgery. We conjecture that a complete system, with a more accurate robot, could be used in vivo. We believe that results taken from the individual studies will result in improvements to pre-operative port placement and robotic design

Is Steam a Modern Heating Medium or a Victorian Hangover?

In the UK many hospitals use steam as a heating medium. It is an accepted fact that steam can carry considerable amounts of heat energy, but is heating by steam really a cost effective and energy efficient method for hospital engineering services? This paper examines some steam and MTHW case studies in terms of energy and operation, and some quantifiable parameters for comparison of the two have been obtained. An important feature revealed by the study is that optimum energy and operational performance for both steam and MTHW systems is directly related to management and maintenance. Other factors affecting the choice of steam are also examined. For example, when choosing between steam and MTHW, how important a factor are those unique hospital applications such as laundries and sterilization equipment, that are traditionally provided for by steam? Interviews were conducted with engineering professionals at a large North-West hospital in order to consider the specialist health service applications for steam. The investigation concludes that although steam retains a Victorian image, in hospital applications its energy and financial performance costs are comparable, and sometimes better than hot water alternatives

Seismology of curved coronal loops with vertically polarised transverse oscillations

Aims. Using a model of vertically polarised fast magnetoacoustic waves in curved coronal loops, the method of coronal seismology is applied to observations of transverse loop oscillations. Methods. A coronal loop is modeled as a curved magnetic slab in the zero plasma-β limit. For an arbitrary piece-wise continuous power law equilibrium density profile, the dispersion relation governing linear vertically polarised fast magnetoacoustic kink waves is derived. The ways in which this model can be used for coronal seismology are explored and applied to two observational examples. Results. The Alfvén speed and equilibrium density profile are determined from observations. It is shown that the mechanism of lateral leakage of fast magnetoacoustic kink oscillations described in this model is efficient. In fact, the damping is so efficient that in order to match predicted values with observational ones, either the loop needs to be highly contrasted or the transverse Alfvén speed profile needs to be close to linear. Possible improvements to make the modeling of lateral wave leakage in loops more realistic, allowing a lower damping efficiency, are discussed

Critical connectivity in banking networks

The financial crisis of 2007-2009 demonstrated the need to understand the macrodynamics of interconnected financial systems. A fruitful approach to this problem regards financial infrastructures as weighted directed networks, with banks as nodes and loans as links. Using a simple banking model in which banks are linked through interbank lending, with an exogenous shock applied to a single bank, we find a closedform analytical solution for the degree at which failures begin to propagate in the network. This critical degree is expressed as a function of four financial parameters: banking leverage; interbank exposure; return on the investment opportunity; and interbank lending rate. While the transition to failure propagation is sharpest with regular networks, we observe it numerically for random and scale-free networks as well. We find that, if the expected number of failures is not strongly dependent on the network topology and is well captured by the notion of critical degree, the frequency of catastrophic cascades (with a single shock inducing all or most banks in the network to fail) tends to be much larger on scale-free networks than on classical random networks. We interpret this finding as a manifestation of the “robust-yet-fragile” property of scale-free networks

Age-related differences in exercise and quality of life among breast cancer survivors

Purpose: Physical activity has become a focus of cancer recovery research as it has the potential to reduce treatment-related burden and optimize health-related quality of life (HRQoL). However, the potential for physical activity to influence recovery may be age-dependent. This paper describes physical activity levels and HRQoL among younger and older women after surgery for breast cancer and explores the correlates of physical inactivity. Methods: A population-based sample of breast cancer patients diagnosed in South-East Queensland, Australia, (n=287) were assessed once every three months, from 6 to 18 months post-surgery. The Functional Assessment of Cancer Therapy-Breast questionnaire (FACTB+4) and items from the Behavioral Risk Factor Surveillance System (BRFSS) questionnaire were used to measure HRQoL and physical activity, respectively. Physical activity was assigned metabolic equivalent task (MET) values, and categorized as 3, p<0.05). Conclusions: Age influences the potential to observe HRQoL benefits related to physical activity participation. These results also provide relevant information for the design of exercise interventions for breast cancer survivors and highlights that some groups of women are at greater risk of long-term sedentary behavior

Wearable technology for bio-chemical analysis of body fluids during exercise

This paper details the development of a textile based fluid handling system with integrated wireless biochemical sensors. Such research represents a new advancement in the area of wearable technologies. The system contains pH, sodium and conductivity sensors. It has been demonstrated during on-body trials that the pH sensor has close agreement with measurements obtained using a reference pH probe. Initial investigations into the sodium and conductivity sensors have shown their suitability for integration into the wearable system. It is thought that applications exist in personal health and sports performance and training