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Full-Text Articles in Engineering

Non-Invasive Diagnostic Measures Of Sensorineural Hearing Loss In Chinchillas, Hannah M. Ginsberg, Satyabrata Parida, Michael G. Heinz Aug 2018

Non-Invasive Diagnostic Measures Of Sensorineural Hearing Loss In Chinchillas, Hannah M. Ginsberg, Satyabrata Parida, Michael G. Heinz

The Summer Undergraduate Research Fellowship (SURF) Symposium

According to the World Health Organization, disabling hearing loss affects nearly 466 million people worldwide. Sensorineural hearing loss (SNHL), which is characterized as damage to the inner ear (e.g., cochlear hair cells) and/or to the neural pathways connecting the inner ear and brain, accounts for 90% of all disabling hearing loss. More concerning is that significant perceptual and physiological aspects of SNHL remain “hidden” from standard clinical diagnostics. Hidden hearing loss (HHL) manifests as the inability to understand speech in loud, noisy environments (e.g., listening in a noisy restaurant) despite a normal audiogram (i.e., normal detection of soft sounds). Recently, …


Neural Coding Of An Auditory Pitch Illusion, Maria Alejandra Barrera, Mark Sayles, Ravinderjit Singh Aug 2018

Neural Coding Of An Auditory Pitch Illusion, Maria Alejandra Barrera, Mark Sayles, Ravinderjit Singh

The Summer Undergraduate Research Fellowship (SURF) Symposium

Pitch is an important perceptual dimension in audition, supporting auditory object segregation, melody recognition and lexical distinction. Huggins’ pitch, for example, is a phenomenon evoked by two sources of broadband noise presented binaurally with an inter-aural phase shift over a narrow frequency band. Huggins’ pitch and other dichotic pitches have been studied extensively using perceptual experiments. Several models have been proposed to explain and predict the perception of pitch; however, no studies have tried to record in vivo neuron responses to Huggins’ pitch (HP) nor have tried to explain how the HP is coded by neurons. The existence of pitches …


Low Power, Low Noise Circuit For Biological Signal Recording, Rachael A. Swenson, Daniel J. Pederson, Pedro Irazoqui Aug 2017

Low Power, Low Noise Circuit For Biological Signal Recording, Rachael A. Swenson, Daniel J. Pederson, Pedro Irazoqui

The Summer Undergraduate Research Fellowship (SURF) Symposium

Implantable devices are ideal for recording biological signals in animal models as they have minimal effect on the animal’s normal behavior during observation. The creation of the circuitry for an implantable device has several restrictions including size, power consumption, and noise reduction. These factors compete against each other, making it necessary to carefully optimize circuit components for a given application. This study evaluates the design of a four-channel analog front end circuit board to record cardiac, neural, and respiratory biological signals. Through a critical analysis of component specifications for the circuit’s components and an evaluation of the circuits’ power and …


Co-Modulation Masking Release Begins In The Auditory Periphery, Kareem R. Hussein, Agudemu Borjigan, Mark Sayles Aug 2017

Co-Modulation Masking Release Begins In The Auditory Periphery, Kareem R. Hussein, Agudemu Borjigan, Mark Sayles

The Summer Undergraduate Research Fellowship (SURF) Symposium

Understanding speech in noisy environments can be difficult, especially for people with hearing loss. The background noise can cover up the sounds of interest. Normally, the auditory system works to alleviate this problem by tagging and then cancelling the noise. Our experiments are aimed at understanding the mechanism of this noise cancellation process. We hypothesize that non-linear signal processing in the mammalian cochlea (the most peripheral part of the auditory system) is the basis of noise cancellation. To test this hypothesis, we measured the responses of auditory-nerve fibers (ANFs) to sounds embedded in background noise with different statistical properties. ANFs …


Gui For Mri-Compatible Neural Stimulator And Recorder, Soo Han Soon, Nishant Babaria, Ranajay Mandal, Zhongming Liu Aug 2017

Gui For Mri-Compatible Neural Stimulator And Recorder, Soo Han Soon, Nishant Babaria, Ranajay Mandal, Zhongming Liu

The Summer Undergraduate Research Fellowship (SURF) Symposium

Functional magnetic resonance imaging (fMRI) and electroencephalography (EEG) are useful tools to analyze brain activities given active stimulation. However, the electromagnetic noise from the MRI distorts the brain signal recording and damages the subject with excessive heat generated on the electrodes attached to the skin. MRI-compatible recording and stimulation systems previously developed at LIBI lab were capable of removing the electromagnetic noise during the imaging process. Previously, the hardware systems had required the integrative software that could control both circuits simultaneously and enable users to easily change recording and stimulation parameters. Graphical user interface (GUI) programmed with computer language informed …


A Proposal For A Wirelessly Powered, Implantable Pressure Sensor And Neural Stimulator For The Control Of Urinary Incontinence, Robert N. Tucker, Christopher J. Quinkert, Pedro P. Irazoqui Aug 2016

A Proposal For A Wirelessly Powered, Implantable Pressure Sensor And Neural Stimulator For The Control Of Urinary Incontinence, Robert N. Tucker, Christopher J. Quinkert, Pedro P. Irazoqui

The Summer Undergraduate Research Fellowship (SURF) Symposium

47 to 53 percent of women over the age of 20 suffer from urinary incontinence, often caused by childbirth-related damage to the pelvic nerve. This uncertainty of when bladder voiding will occur causes social anxiety and can compromise quality of life. This study explores one method to restore the ability to sense the need to urinate and prevent unwanted voiding. We propose a device to measure pressure due to bladder content as the difference between pressure in the bladder and pressure in the abdominal cavity. Integrated circuits, biocompatible packaging, and wireless radiofrequency powering allow for a fully implantable device to …


Cold Atmospheric Pressure Plasmas For Food Applications, Michael V. Lauria, Russell S. Brayfield Ii, Ronald G. Johnson, Allen L. Garner Aug 2016

Cold Atmospheric Pressure Plasmas For Food Applications, Michael V. Lauria, Russell S. Brayfield Ii, Ronald G. Johnson, Allen L. Garner

The Summer Undergraduate Research Fellowship (SURF) Symposium

Successfully distributing shelf food requires treatment to eliminate microorganisms. Current chemical methods, such as chlorine wash, can alter food quality while only being effective for a limited time. Cold atmospheric pressure plasmas (CAPs) can eradicate the microorganisms responsible for food spoilage and foodborne illness. Optimizing CAP treatments requires understanding the reactive species generated and relating them to eradication efficiency. Recent studies have used optical emission spectroscopy (OES) to determine the species generated in a sealed package that would hold food. In this study,we supplement the OES results with optical absorption spectroscopy (OAS) using the same gases (helium, nitrogen, compressed air, …


Fabrication And Evaluation Of Magnetic Micro Actuators For Implantable Self-Clearing Glaucoma Drainage Devices, Haritha Ramadorai, Hyunsu Park, Hyowon Lee Aug 2016

Fabrication And Evaluation Of Magnetic Micro Actuators For Implantable Self-Clearing Glaucoma Drainage Devices, Haritha Ramadorai, Hyunsu Park, Hyowon Lee

The Summer Undergraduate Research Fellowship (SURF) Symposium

According to the World Health Organization, glaucoma is the second leading cause of blindness in the world. It currently affects more than 2.7 million people in the United States alone and over 79.6 million people worldwide are estimated to be inflicted by this debilitating disease by 2020. Glaucoma patients are often characterized with elevated intraocular pressure (IOP) and are treated with implantation of glaucoma drainage devices (GDD) to maintain optimum IOP. Although initially effective at delaying glaucoma progression, contemporary GDD often lead to numerous complications and only 50% of implanted devices remain functional after 5 years. Biofouling is seen to …


Pathway By Which Vagus Nerve Stimulation Of B Fibers Affects Heart Rate, Kelsey Wasilczuk, Matthew Ward, Pedro Irazoqui Aug 2016

Pathway By Which Vagus Nerve Stimulation Of B Fibers Affects Heart Rate, Kelsey Wasilczuk, Matthew Ward, Pedro Irazoqui

The Summer Undergraduate Research Fellowship (SURF) Symposium

Heart failure (HF) affects over 5 million adults in the United States. Many HF patients have a high resting heart rate, which is correlated with a high mortality rate. In recent years, vagus nerve stimulation (VNS) has become an increasingly researched therapy to reduce the resting heart rate of HF patients. However, current dosage given during VNS is increased incrementally at the doctor’s office until side effects present themselves in a patient. In addition, the means by which the therapy works is not completely understood. To better understand the therapy’s mechanisms, the right cervical vagus nerve of several Long Evans …


Mechanical Reliability Of Implantable Polyimide-Based Magnetic Microactuators For Biofouling Removal, Christian G. Figueroa-Espada, Qi Yang, Hyowon Lee Aug 2016

Mechanical Reliability Of Implantable Polyimide-Based Magnetic Microactuators For Biofouling Removal, Christian G. Figueroa-Espada, Qi Yang, Hyowon Lee

The Summer Undergraduate Research Fellowship (SURF) Symposium

Hydrocephalus is a neurological disorder that typically requires a long-term implantation of a shunt system to manage its symptoms. These shunt systems are notorious for their extremely high failure rate. More than 40% of all implanted shunt systems fail within the first year of implantation. On average, 85% of all hydrocephalus patients with shunt systems undergo at least two shunt-revision surgeries within 10 years of implantation. A large portion of this high failure rate can be attributed to biofouling-related obstructions and infections. Previously, we developed flexible polyimide-based magnetic microactuators to remove obstructions formed on hydrocephalus shunts. To test the long-term …


The Effects Of Vagus Nerve Stimulation On Neuroinflammation In Epilepsy, Elizabeth A. St. Clair, Gabriel O Albors, Pedro Irazoqui Dr., Amy Brewster Aug 2015

The Effects Of Vagus Nerve Stimulation On Neuroinflammation In Epilepsy, Elizabeth A. St. Clair, Gabriel O Albors, Pedro Irazoqui Dr., Amy Brewster

The Summer Undergraduate Research Fellowship (SURF) Symposium

Epilepsy is a neurological disorder characterized by chronic, unexplainable seizures. Recurring epileptic seizures are associated with long-term structural damage and cognitive deficits, and can even lead to sudden, unexplainable death. Approximately 30% of epilepsy cases are not responsive to medication. Epileptic seizures often induce inflammation in the brain and may increase the frequency of future seizures, resulting in a detrimental cycle. Vagus nerve stimulation (VNS) is a non-pharmaceutical treatment method for epilepsy that has been shown to reduce inflammation in peripheral pathways. The role of VNS in the modulation of neuroinflammation has yet to be demonstrated experimentally. To explore this, …


Towards In Situ Measurements Of Platinum Dissolution Using Metallothionein-Based Biosensor, Stephanie Cernera, Hyowon Lee Aug 2015

Towards In Situ Measurements Of Platinum Dissolution Using Metallothionein-Based Biosensor, Stephanie Cernera, Hyowon Lee

The Summer Undergraduate Research Fellowship (SURF) Symposium

Platinum-based (Pt) electrodes are used ubiquitously in neurostimulation for their high charge capacity and safety. However, Pt electrodes are known to dissolve during stimulation in the presence of chloride (Cl) to form Pt-Cl byproducts. These byproducts may have deleterious effects on surrounding tissue by preventing cell division and causing apoptosis. Several studies have quantified the amount of neurostimulation-induced Pt dissolution in vivo using various analytical methods; however, these approaches require disruptive sampling of tissue. Periodic measurements from a stimulating electrode using an in situ sensor may provide additional insights into Pt dissolution process. To create the sensor for detecting Pt …


Implantable Device For Wireless Regulation Of The Bladder Through Pelvic Nerve Stimulation, Kelsey C. Bayer, Chris Quinkert, Pedro Irazoqui Aug 2015

Implantable Device For Wireless Regulation Of The Bladder Through Pelvic Nerve Stimulation, Kelsey C. Bayer, Chris Quinkert, Pedro Irazoqui

The Summer Undergraduate Research Fellowship (SURF) Symposium

Urinary incontinence (UI) is the involuntarily urination that usually effects older people or is the result of an injury. UI affects more than eleven million people and the cost of incontinence management in the United States in 2000 was $19.5 billion. Where conventional physical therapies have failed, pelvic nerve stimulation is a promising form of regulating the bladder long term. Piezoresistive pressure sensors consist of two variable resistance values and two known resistance values that are represented on a daughterboard. This unknown resistance represents the change in pressure. The filling and voiding of the bladder was characterized through acute surgeries. …


An Implantable Device To Regulate Urination Through Deep Brain Stimulation, Jesse E. Bucksot, Muhammad A. Arafat, Pedro Irazoqui Aug 2015

An Implantable Device To Regulate Urination Through Deep Brain Stimulation, Jesse E. Bucksot, Muhammad A. Arafat, Pedro Irazoqui

The Summer Undergraduate Research Fellowship (SURF) Symposium

Urinary Incontinence (UI) is a disease in which patients lose control of their bladder. It is particularly common in elderly women having a prevalence of as much as 30% to 50% [1]. Many of these patients are left without successful treatment. A recent study has shown a new option for treatment that consists of deep brain stimulation (DBS) at a site known as the periaqueductal gray (PAG) [2, 3]. To test the effectiveness of this treatment, chronic stimulation of the PAG should be used in animals to see if it can reliably prevent micturition in the long term. A device …


Thin-Film Sol-Gel As Controlled Delivery Platform For Neural Microelectrodes, Margaret A. Harden, Matthew D. Mcdermott, Kevin J. Otto Aug 2014

Thin-Film Sol-Gel As Controlled Delivery Platform For Neural Microelectrodes, Margaret A. Harden, Matthew D. Mcdermott, Kevin J. Otto

The Summer Undergraduate Research Fellowship (SURF) Symposium

Long-term efficacy of neural implantation devices is a persisting challenge in neural engineering and rehabilitation. Upon implantation of a neural device, the foreign body response (FBR) is triggered and glial cells form a sheath around the electrode array. This sheath isolates the array from the rest of the brain both mechanically and electrically. Tetramethyl orthosilicate (TMOS), a thin-film polymer, has been shown to not negatively impact the impedance and charge-carrying capacity, as well as offer a controlled delivery method to deliver pharmaceuticals to mitigate inflammation without significant effect to device design. Using an in vitro protein delivery model to analyze …


Chronic Brain Stimulation Using Micro-Ecog Devices, Hayden C. Carney, Roy Lycke, Kevin J. Otto, Amelia A. Schendel, Justin Williams Aug 2014

Chronic Brain Stimulation Using Micro-Ecog Devices, Hayden C. Carney, Roy Lycke, Kevin J. Otto, Amelia A. Schendel, Justin Williams

The Summer Undergraduate Research Fellowship (SURF) Symposium

Recording and stimulating brain activity has had great success both as a research tool and as a clinical technique. Neural prosthetics can replace limbs, restore hearing, and treat disorders like Parkinson’s and epilepsy, but are relatively crude. Current neural prosthetic systems use penetrating electrodes to achieve high precision, but the invasive nature of these devices provoke a strong immune response that limits chronic use. (Polikov et al) In our study we evaluate micro-electrocortiographic (micro-ECoG) devices which sit under the skull and on the surface of the brain for stimulation over chronic timescales. We anticipate these devices with their less invasive …


Medical Applications Of Mrc, Kyle Thackston, Henry Mei, Pedro Irazoqui Aug 2014

Medical Applications Of Mrc, Kyle Thackston, Henry Mei, Pedro Irazoqui

The Summer Undergraduate Research Fellowship (SURF) Symposium

Consistent powering is a limiting reagent for many medical implants and sensors. Powering in-vivo devices in animal studies requires either transcutaneous wiring (limiting mobility and increasing the chance of infection) or an implanted battery (limited lifetime and limits size of device). Wireless power transfer (WPT) would be able to overcome these challenges and permit the use of more advanced implantable devices in a research setting. Magnetic resonance coupling (MRC), an advanced form of inductive charging, allows good transfer efficiencies over significant air gaps, but works best a specific location and frequency, limiting mobility in animal studies. Using band-pass filter theory, …


The Efficacy And Optimization Of Somatosensory Intracortical Microstimulation In Rats, Sean P. Mcdowell, Ryan S. Verner, Kevin J. Otto Dr. Oct 2013

The Efficacy And Optimization Of Somatosensory Intracortical Microstimulation In Rats, Sean P. Mcdowell, Ryan S. Verner, Kevin J. Otto Dr.

The Summer Undergraduate Research Fellowship (SURF) Symposium

Demand exists for brain-machine interfaces that offer a wide range of sensory feedback along with volitional motor control to individuals with limited control of natural sensory or motor function. As these sensorimotor devices are developed, it is necessary to improve the interaction between the prostheses and higher-level cortical structures. Optimizing these somatosensory stimulation parameters will require the use of a high-throughput experimental design. To address this, one Sprague-Dawley rat was trained to respond to auditory stimuli during a conditioned-avoidance behavior task and then implanted with a penetrating microelectrode array in the part of the somatosensory cortex corresponding to the left …


Toward An Optogenetic Autonomous Nerve Control (Oanc) System, Malika S. Datta, Matthew Ward, Steven Lee, Kevin Seburn, Pedro Irazoqui Oct 2013

Toward An Optogenetic Autonomous Nerve Control (Oanc) System, Malika S. Datta, Matthew Ward, Steven Lee, Kevin Seburn, Pedro Irazoqui

The Summer Undergraduate Research Fellowship (SURF) Symposium

Optogenetics is a developing field in neuroscience, where nerves are stimulated through optical instead of electrical signals, allowing for a more selective action of nerve populations [Aravanis et al, 2007]. In the context of electrical stimulation, the autonomous nerve control (ANC) system has been used successfully, first to map the response of different nerve fibers to create a Nerve Activation Profile, and then to use this profile in recruiting specific nerve fibers in a controlled way [MP Ward et al, unpublished manuscript in preparation]. The objective of the present project is to apply the ANC system to optical stimulation thus …