Tutorials will be presented on Thursday Nov 10, 2011.
Tutorials are included within the full registration price.
“Solid-state electronics and single-molecule biophysics”
Ken Shepard, Columbia University
Abstract: Technological advances in the development of fluorescent probes, solid-state imagers, and microscopy techniques have enabled biomolecular studies at the single-molecular level. Fluorescent techniques use light as an intermediary and rely on imagers for interfacing to the solid-state. More intriguing are new electronic techniques for single-molecule detection based on charge. In particular, both nanopores and nanotube field-effect transistors have demonstrated capabilities for single-molecule detection. Here, we review and discuss the potential advantages these direct solid-state interfaces bring to biophysics in terms of transducer gain, signal-to-noise ratio, specificity and spatial resolution.
“Solid-state and Bio systems Interface”
Donhee Ham, Harvard University
Abstract: The complexity, programmability, small size, and low cost of solid-state devices in direct contact with biological samples and living organisms can offer new capabilities in analyzing biomolecules for, e.g., personalized medicine, and in examining the dynamics/informatics of a large group of interconnected neurons for neurobiology. I would like to review some recent developments along this direction. This will include some past and on-going works in my research group at Harvard. Our CMOS RF biomolecular sensor based on nuclear magnetic resonance (NMR) uses a low-noise spin coupling to detect biomolecules such as cancer marker proteins: it is 1200 times smaller yet 150 times more sensitive than the state-of-the-art commercial NMR system. Our silicon + electrochemistry work is aimed at developing massively parallel device arrays to analyze proteins, DNA, and neural dynamics, using large-strength charge coupling, in a low-cost, chip-scale platform.
“Integrated Biopotential Amplifiers: Architecture, Performance, and Testing”
Reid R. Harrison, Intan Technologies, LLC
Abstract: Monitoring the electrical potentials produced by the body can provide a wealth of information for both scientific and clinical endeavors. Recent advances in microelectrodes have enabled the development of fully integrated electrophysiological recording systems. Designing integrated circuits to observe many biological signals in situ presents many technological challenges. Power must be minimized to allow for the limited power sources available and, above all, to prevent local tissue heating that could kill cells. Since multi-electrode arrays monitor weak extracellular voltages, amplifiers must be able to resolve ac signals in the microvolt range while rejecting large dc offsets present at the electrode-tissue interface. In some applications low frequency signals are important, yet few off-chip components can be tolerated in implantable devices. Front-end amplifiers cannot be multiplexed and thus must be optimized for low power, small silicon area, and high common-mode rejection. Simultaneous recording from many electrodes typically requires the use of analog multiplexers, and even these prosaic circuits can pose challenges for low-power design. I will outline a variety of circuit architectures that address these unique challenges and investigate the multidimensional trade-offs between power and performance in biopotential amplifiers. I will also discuss practical benchtop testing practices for accurately measuring the performance of these amplifiers.
“Electrical Stimulation of the Retina as Treatment for Blindness”
James Weiland, University of Southern California
Abstract: This tutorial will review basics of neural stimulation, with special emphasis on electrical stimulation of the retina. Retinitis pigmentosa (RP) and age-related macula degeneration (AMD) lead to the degeneration of the light sensitive cells of the eye (photoreceptors), resulting in a significant visual deficit for the afflicted individual. In a normal eye, retinal photoreceptors initiate a neural signal in response to light. In a retina affected by RP or AMD, the photoreceptors are absent, but other cells of the retina remain present in large numbers. Current clinical trials are investigating the feasibility of replacing the function of the photoreceptors with an electronic device that will electrically stimulate the remaining cells of the retina to generate visual perceptions. In tests with human volunteers with little or no light perception, we have used a prototype retinal prosthesis with a limited number of stimulating electrodes to create the perception of discrete spots of light. Subjects were able to distinguish basic shapes and to detect motion. Based on these encouraging results, the current focus is being shifted from feasibility studies to the development of a high-resolution retinal prosthesis which will be capable of stimulating the retina at thousands of individual points. Simulations of prosthetic vision predict that 1000 electrodes will be needed to restore visual function such as face recognition, reading, and mobility. The proposed retinal prosthesis system would include an external video camera to capture an image and electronics to code the image and transmit the coded data to an implanted system. The implanted electronics will receive the data, decode the signal and generate the desired current pulse pattern for the stimulating array.
“Wireless Real-time Monitoring of Brain Neurochemistry
Pedram Mohseni, Case Western Reserve University
Abstract: New enabling technologies for monitoring and manipulation of chemical and electrical neural activity in the brain can provide a holistic image of neural signal pathways. Such new capabilities could usher in a new realm of possibilities for studies at their most fundamental levels by probing neuronal communication at microscopic scales in real time, with applications in both basic neuroscience and clinical research. This presentation will first provide an introduction to neural engineering and describe the fundamentals of brain interfacing in both electrical and chemical paradigms. The talk will then showcase one example of engineered devices for real-time, concurrent sensing of neurochemical signals and electrical action potentials in the brain of anesthetized and ambulatory rats. Challenges in high-site-density, wireless monitoring of brain neurochemistry will be highlighted, and emerging wireless communication technologies to potentially address these challenges will be discussed.
"Transcutaneous Power and Data Transmission to Implantable Microelectronic Devices"
Maysam Ghovanloo, Georgia Institute of Technology
Abstract: Unlike pacemakers, extreme size constraints and high power consumption prevent many implantable microelectronic devices (IMD) such as cochlear and retinal implants from using primary batteries as their energy source. Moreover, such devices need to deliver a sizable volume of information from external artificial sensors to the nervous system while interfacing with large neural populations at high stimulus rates. Nonetheless, the skin barrier should remain intact and the temperature should be maintained well within the safe limits. In this tutorial I will cover the fundamentals of efficient power and wideband data transmission across inductive links. I will discuss the optimization procedure to achieve the highest possible power transmission efficiency using two, three, and four coil systems. I will review some of the latest techniques to establish wideband bidirectional communication links across the skin, and will also touch on efficient methods to convert the received AC power on the IMD to DC and stabilize it at a desired level despite coupling variations due to coil misalignments.