Topics

Dr Rona Chandrawati - The University of Sydney, Australia

rona.chandrawati@sydney.edu.au

Title: Biomimicry: Innovations in Diagnostics Inspired by Nature

Abstract: The development of diagnostic tools for early detection of diseases have been constantly emerging, however one of the biggest challenges faced worldwide is that tests developed are still not sensitive enough. With the paradigm shift from disease control to eradication, the search for more sensitive and reliable diagnostic tools continues and has fuelled the interdisciplinary fields of biomimicry and bionanotechnology. This talk will describe our recent developments in the design of nanomaterial-based biosensors. We report a highly sensitive assay for the determination of blood coagulation Factor XIII activity using peptide-functionalized gold nanoparticles. Furthermore, we have recently developed an assay based on a biomimetic approach for the selective and sensitive detection of influenza biomarkers at subnanomolar concentrations via membrane fusion mechanism. The new systems present exciting opportunities for the development of early warning point-of-care diagnostic technologies.


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Dr Doan Trang Nguyen - The University of Sydney, Australia

d.nguyen@sydney.edu.au

Title: Non-invasive ventilation/perfusion imaging with Electrical Impedance Tomography (EIT)

Abstract: Recent studies have shown high correlation between pulmonary perfusion mapping with impedance contrast enhanced Electrical Impedance Tomography (EIT) and standard perfusion imaging methods such as Computed Tomography (CT) and Single Photon Emission Computerized Tomography (SPECT). EIT has many advantages over standard imaging methods as it is highly portable and non-invasive. Contrast enhanced EIT uses hypertonic saline bolus instead of nephrotoxic contrast medium that are utilized by CT and nuclear Ventilation/Perfusion (V/Q) scans. However, current implementation of contrast enhanced EIT requires induction of an apnea period for perfusion measurement, rendering it disadvantageous compared with current gold standard imaging modalities. In the present paper, we propose the use of a wavelet denoising algorithm to separate perfusion signal from ventilation signal such that no interruption in patient's ventilation would be required. Furthermore, right lung to left lung perfusion ratio and ventilation ratio are proposed to assess the mismatch between ventilation and perfusion for detection of Pulmonary Embolism (PE). The proposed methodology was validated on an ovine model (n=3, 83.7±7.7 kg) with artificially induced PE in the right lung. The results showed a difference in right lung to left lung perfusion ratio between baseline and diseased states in all cases with all paired t-tests between baseline and PE yielding p <; 0.01, while the right lung to left lung ventilation ratio remained unchanged in two out of three experiments. Statistics were pooled from multiple repetitions of measurements per experiment.


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Boris Rubinsky - University of California Berkeley, USA

rubinsky@me.berkeley.edu

Title: Electrical impedance tomography and electrical tissue properties based imaging

Title: Micro electroporation and irreversible electroporation

Abstract: Electric currents and fields can serve as actuators and sensors of biological systems. Our group is involved in both modalities, and this talk will describe the work, as summarized below. An important application of electric fields, in medicine and biotechnology, is their use to permeabilize the cell membrane in a process known as electroporation. Electroporation can be reversible or irreversible, as a function of electric field strength and delivery time. Reversible electroporation is used to introduce chemical species that normally do not penetrate the cell membrane, such as genes, into the cell.


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Seward Rutkove - Harvard Medical School, USA

srutkove@bidmc.harvard.edu

Title: Electrical impedance myography: past, present, and future.

Abstract: Easily applied techniques for the assessment and quantification of muscle condition are needed as diagnostic tools, as biomarkers in clinical trials, and as methods to assess individual patient response during treatment and rehabilitation. Electrical impedance myography (EIM) is a recently developed, non-invasive and user-friendly technique that is beginning to find wide application in patients with primary neuromuscular diseases (e.g., muscular dystrophy and amyotrophic lateral sclerosis) and in individuals with other conditions impacting strength and fitness, including sarcopenia and deconditioning. This talk will review the background of the technique, past and recent data supporting its value in a wide range of disorders, and plans for its future development and wider application, as well as ongoing challenges.


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Dr Warren Smith - Ti² Medical

samadhapacifica@fastmail.fm

Title: Development path of an investigational bioimpedance device: a long and winding road.

Abstract: Although the history of electrical impedance measurement on the human body extends beyond 100 years, and techniques such as tetrapolar BIA (bioelectrical impedance analysis) are now routinely used for body composition determination, there remain a surprising number of basic questions that are still to be answered. For example, the long-range current paths in living human are yet to be identified. And why is it that BIA whole-body phase angle, simply measured from hand to foot, turns out to be a powerful biomarker of global wellness and a useful prognostic indicator in case of illness? Also, what is the physical basis of the strong positive correlation (typically r = 0.6 ~ 0.7) between whole-body BIA resistance and reactance at f = 50kHz? And there are plenty of other mysteries besides. In recent years, our company has been developing devices intended to not only help throw some light on such basic questions at a research level but also with the anticipation that new useful downstream commercial products may be an outcome as well. Aspects of the journey so far, including detours, are to be presented.


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Dr Michael Cejnar - MicroPace Australia

m.cejnar@micropace.com.au

Title: Electroporation for Ablation of Cardiac Arrythmias

Abstract: Atrial fibrillation is the most common cardiac arrythmia worldwide, reducing quality of life for millions of people and presenting significantly increased danger of stroke and other complications in a subset of those. This arrythmia is commonly treated with antiarrythmic drugs and anticoagulants, implantable rhythm devices (pacemakers), and most commonly, intracardiac radiofrequency (RF) ablation, which is a form of electrocautery. While RF ablation is effective, there are drawbacks. The tissue is heated to high temperatures causing cell death, effectively destroying the areas of tissue that 'short circuit' and allow the arrythmia to propogate. But this heat causes collateral damage to surrounding tissue structures which can, over time, lead to negative remodeling effects of the atrium. The method has a narrow therapeutic window - too much heat causes excessive necrosis and possible ulceration, and too little is an ineffective cure. It also lacks some precision, and can damage or destroy adjacent anatomy such as damage to the phrenic nerve or esophagus, the latter of which can be a fatal complication. This technique of 'point by point' RF ablation is also very time consuming. Ablation by electroporation seeks to minimise these complications and increase the effectiveness and long-term freedom from arrythmia. It can possibly do this by providing a method that has higher local precision of lesion formation, reduced damage to non-myocardial tissue, and the potential to 'trial' lesions with lower voltage pulses to temporarily disrupt the cells before locking in a higher voltage pulse for permanent lesions. This talk discusses the brief history of the technology, the state of the art so far, and the advancements required to reach a clinical solution.


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Emeritus Professor Hans Coster - School of Chemical and Biomolecular Engineering, University of Sydney

hans.coster@sydney.edu.au

Title: Electrical breakdown and electroporation in cell membranes: An overview of experiments, theory, and novel applications.

Abstract: The V-I characteristics of the membranes of cells, measured using pulsed currents, display a phenomenon whereby at a well defined electric potential difference of around 500 mV the cell membrane undergoes a reversible electrical breakdown. This phenomenon was originally referred to as "punchthrough". The electrical breakdown potential is also temperature dependent, decreasing with increasing temperature. The electrical breakdown is in itself not dependent on the power dissipated in the cell membrane by the current pulses but rather a critical voltage dependent phenomenon. Electrical breakdown, if sustained for milliseconds, or even tens of microseconds, leads to the formation of transient pores in the cell membrane. This is referred to as electroporation and promotes rapid exchange of small molecules and ions and electro-osmotic readjustments. The latter, under certain conditions, can have catastrophic effects on cells. More moderate electroporation allows exchange of macro molecules such as DNA and is commonly used in genetic engineering to transfect DNA into cells. It is also possible to use electroporation to fuse two cells and such electro-fusion methods have been successfully used to produce hybridomas. Electroporation also increases the susceptibility of cells to cytotoxic molecules such as chlorine and has been demonstrated to be a possible effective, electro-disinfection, method.
An overview is given of the nature of the breakdown phenomenon and results are presented of some biotechnological applications of electroporation.