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Articles 1 - 4 of 4
Full-Text Articles in Engineering
Mechanical Testing Device For Viscoelastic Biomaterials, Jeff D. Berg
Mechanical Testing Device For Viscoelastic Biomaterials, Jeff D. Berg
Department of Mechanical and Materials Engineering: Dissertations, Theses, and Student Research
Nearly all biologic tissues exhibit viscoelastic behavior. This behavior is characterized by hysteresis in the response of the material to load or strain. This information can be utilized in extrapolation of life expectancy of vascular implant materials including native tissues and synthetic materials. This behavior is exhibited in many engineering materials as well such as the polymers PTFE, polyamide, polyethylene, etc. While procedures have been developed for evaluating the engineering polymers the techniques for biologic tissues are not as mature. There are multiple reasons for this. A major one is a cultural divide between the medical and engineering communities. Biomedical …
Frequency Response And Gain Enhancement Of Solid-State Impact-Ionization Multipliers (Sims), Joshua L. Beutler
Frequency Response And Gain Enhancement Of Solid-State Impact-Ionization Multipliers (Sims), Joshua L. Beutler
Theses and Dissertations
A study of the frequency response and gain of Solid-state the Impact-ionization Multiplier (SIM). The SIM generates current gain via impact ionization also known as avalanche gain. The SIM provides low noise amplification from an arbitrary current source. In the case of this study, current sources consisted of photodiodes optimized for a particular wavelength of light. The SIM is fabricated from silicon and enjoys the low noise, low carrier transit time advantages of conventional silicon impact ionization devices while amplifying current from a photodiode of a different material. This is advantageous because ideal detection and multiplication regions cannot always be …
Pspice Simulation Of An Electro-Acoustic Communications Channel, Graham Wild, Steven Hinckley
Pspice Simulation Of An Electro-Acoustic Communications Channel, Graham Wild, Steven Hinckley
Research outputs pre 2011
In this paper, we present results from a circuit simulation of a proposed electro-acoustic communications channel. The communications channel was modeled in PSpice using Redwood's version of Mason's equivalent circuit. The simulations used binary phase shift keyed communications signals with a carrier frequency of 1.12 MHz. Results obtained from the model are comparable with the results obtained experimentally. The frequency response of the model matched the measured frequency response, predicting lower frequency resonances obtained in the experimental data. The transient response of the model compares almost identically with the transient response observed experimentally. This is a significant characteristic as the …
Wireless Acoustic Communications And Power Supply For In-Vivo Biomedical Devices, Graham Wild, Steven Hinckley
Wireless Acoustic Communications And Power Supply For In-Vivo Biomedical Devices, Graham Wild, Steven Hinckley
Research outputs pre 2011
Pacemakers are common biomedical devices used in the treatment of specific cardiovascular problems. Current research in biomedical engineering is investigating the use of so called brain pacemakers to regulate conditions such as Parkinson's and other neurological conditions. In this paper, we demonstrate the principle of acoustic communications and power harvesting, in vivo. The signals are intended to be used for fixed in vivo biomedical devices, such as pacemakers, were wired and wireless RF communications cannot be used. Results show the performance of the communications channel. The frequency response, transfer function and transient response (at resonance) of the communications channel were …