Biomedical Devices and Instrumentation Commons^™

Use Of Bioheat Modeling To Characterize And Optimize Implantable Medical Devices And Neuromodulation Technologies, Adantchede Louis Zannou

Dissertations and Theses

Medical device development includes prototyping, benchtop characterization, preclinical studies, and clinical trials. Understanding the limitations and potential adverse effects of medical devices prior to their administration in humans is a crucial first step. Optimizing medical devices is essential to employing technology and improving patients care. Computational modeling is widely adopted as a powerful tool to predict stimulation/recording parameter optimization, rapid electrode/device prototyping, investigating novel mechanism of action, and testing working principles of any medical devices. Many implantable neuromodulation technologies including Spinal Cord Stimulation (SCS), which provide substantial therapeutic benefit for patient population with lower back pain, produces heat via the …

Low-Intensity Ultrasonic Neuromodulation Of The Rat Hippocampus, Duc Nguyen

Dissertations and Theses

Techniques to non-invasively modulate brain activity are important for mapping human brain circuits, and also for the treatment of a host of neurological and psychiatric disorders marked by aberrant brain activity. Though a wide range of techniques for non-invasive neuromodulation have been proposed, the conventional approaches suffer from significant limitations. Most notably, focal stimulation of deep brain regions is presently only possible with invasive optogenetic and chemogenetic approaches that require craniotomies and genetic access to the brain.

Transcranial focused ultrasound stimulation (tFUS) possesses many of the characteristics desirable from a neuromodulation approach: non-invasiveness, a spatial resolution in the order of …

Blood–Brain Barrier Breakdown And Astrocyte Reactivity Evident In The Absence Of Behavioral Changes After Repeated Traumatic Brain Injury, Celeste Dunn, Nasya Sturdivant, Sara Venier, Syed Ali, Jeffery Wolchok, Kartik Balachandran

Biomedical Engineering Faculty Publications and Presentations

Repeated traumatic brain injuries (TBIs) cause debilitating effects. Without understanding the acute effects of repeated TBIs, treatment options to halt further degeneration and damage cannot be developed. This study sought to examine the acute effects of blood–brain barrier (BBB) dysfunction, edema, inflammation and behavioral changes after either a single or double TBI using a C57BL/6 mouse model. We examined the effects of one or two TBIs, of either a mild or moderate severity. Double injuries were spaced 7 days apart, and all analysis was performed 24 h post-injury. To examine edema and inflammation, protein levels of glial fibrillary acidic protein …

Development Of Light Actuated Chemical Delivery Platform On A 2-D Array Of Micropore Structure, Hojjat Rostami Azmand, Hojjat Rostami Azmand

Dissertations and Theses

Localized chemical delivery plays an essential role in the fundamental information transfers within biological systems. Thus, the ability to mimic the natural chemical signal modulation would provide significant contributions to understand the functional signaling pathway of biological cells and develop new prosthetic devices for neurological disorders. In this paper, we demonstrate a light-controlled hydrogel platform that can be used for localized chemical delivery in a high spatial resolution. By utilizing the photothermal behavior of graphene-hydrogel composites confined within micron-sized fluidic channels, patterned light illumination creates the parallel and independent actuation of chemical release in a group of fluidic ports. The …

Estimating Affective States In Virtual Reality Environments Using The Electroencephalogram, Meghan R. Kumar

Theses and Dissertations

Recent interest in high-performance virtual reality (VR) headsets has motivated research efforts to increase the user's sense of immersion via feedback of physiological measures. This work presents the use of electroencephalographic (EEG) measurements during observation of immersive VR videos to estimate the user's affective state. The EEG of 30 participants were recorded as each passively viewed a series of one minute immersive VR video clips and subjectively rated their level of valence, arousal, dominance, and liking. Correlates between EEG spectral bands and the subjective ratings were analyzed to identify statistically significant frequencies and electrode locations across participants. Model feasibility and …

Novel Tools For Analysis Of Disordered Sleep And Motor Behavior In Preclinical Models Of Disease, Dillon M. Huffman

Theses and Dissertations--Biomedical Engineering

Subtle changes in sleep architecture can accompany and be symptomatic of various diseases or disorders. Understanding the complex interactions between sleep and health requires the ability to characterize sleep, probe its underlying mechanisms through perturbation, and quantify dependent physiological outcomes. Rodent models have come to be accepted as a valuable tool for preclinical investigations. However, experimental tools to accomplish such research typically rely on laborious methods that limit throughput and flexibility. Thus, research tools that minimize workload could be of great value to the research community and expedite investigation of the underlying mechanisms of sleep and further the development of …

Ecg Monitoring In Athletes, Jalal Jwayyed, Kelly Purgason, Joseph Linder, Annamarie Alfery, Silvia Furman

Williams Honors College, Honors Research Projects

Athletes and medical personnel need reliable methods to monitor vital signs and detect potentially life-threatening issues before they occur. Electrocardiograph (ECG) monitors are currently the best method of detecting heart-related health issues. Current ECG monitors worn by athletes are difficult to use and lack the ability to track ECGs in real time. Through research and interviews with various clinicians, further problems have been identified that include poor electrode adhesion, and a lack of compatibility with the equipment worn by athletes. Our team proposes to develop solutions that will improve performance and comfort associated with ECG monitors for athletic applications. This …

Detection Of Standing And Sitting Variations Based On In-Socket Piezoelectric Sensors For Transfemoral Amputees, Alnusairi Tawfik Yahya

Student Works (2020-2029)

A transfemoral prosthesis is required to assist amputees to perform activities of daily living (ADL). The purely mechanical or passive prosthesis has some drawbacks such as consumption of high metabolic energy and limitations in mimicking normal dynamics and kinematics of gait pattern. In contrast, the active prosthesis offers better performance and consumes less metabolic energy. However, recent active prosthesis uses surface electromyography as its sensory system which requires massive preparation work, causes sores to the patient by its electrodes and requires a lot of computation to extract meaningful features. This thesis focuses on developing signal conditioning circuitry to classify six …

Mechanical Analysis Of In Vitro Tbi Models, Dana Hamed

Honors Scholar Theses

This work details the damage done to cells when mechanically hit. The goal was to mechanically analyze in vitro traumatic brain injury (TBI) models. Parts were designed in SolidWorks to create the machine that is used to induce this damage on the cells. A force applicator that uses a 3D-printed micro-hammer to apply force on the brain cells that are being tested was created. Mechanical trauma experimentation was performed with the force applicator, while a high-speed camera recorded the damage, in order to analyze TBI models. Displacement along the scaffold can be tracked from multiple video frames. With these results, …

Investigation Of Dielectric Properties Of Urine For Pregnancy And Bladder Cancer Detection, Chao Zhe Zhu

Student Works (2020-2029)

Detection and monitoring of pregnancy and bladder cancer are important for medical treatment and nursing. Urine has diagnostic and prognostic values for pregnancy and bladder cancer due to the presence of biomarkers. This study investigated the dielectric properties of human urine and compared them between two groups: 1) non-pregnant healthy female volunteers and pregnant healthy female volunteers, and; 2) healthy subjects and patients with bladder cancer. An open-ended probe network analyzer was used to measure the urine dielectric constant (Ɛ’) and dielectric loss (Ɛ’’) at microwave frequency ranging from 0.2GHz to 50GHz at 25˚C (room temperature), 30˚C and 37˚C (body …

Single-Cell Impedance Spectroscopy, David Paul Lange

Master's Theses

Impedance spectroscopy (IS) is an important tool for cell detection and characterization in medical and food safety applications. In this thesis, the Cal Poly Biofluidics Lab’s impedance spectroscopy system was re-evaluated and optimized for single-cell impedance spectroscopy. To evaluate the IS system, an impedance spectroscopy bioMEMS chip was fabricated in the Cal Poly Microfabcrication lab, software was developed to run IS experiments, and studies were run to validate the system. To explore IS optimization, Maxwell’s mixture theorem and the Schwartz-Christoffel transform were used to calculate an analytic impedance solution to the co-planar electrode system,a novel volume fraction to account for …

Impedance-Based Microfluidic Platform For Quantitative Biology, Amin Mansoorifar

Mechanical Engineering Research Theses and Dissertations

Dielectric properties of biological cells are functions of cellular structure, content, state, and phenotype. Dielectric spectroscopy (DS) is a nondestructive method to characterize dielectric properties by measuring impedance data over a frequency range. This method has been widely used for various applications such as counting, sizing, and monitoring biological cells and particles. Recently, this method has been suggested to be utilized in various stages of the drug discovery process due to its low sample consumption and fast analysis time.

In this thesis, we have developed a lab-on-a-chip device that uses an electro-activated microwells array for capturing, making DS measurements on, …

Neurostimulator With Waveforms Inspired By Nature For Wearable Electro-Acupuncture, Jose Aquiles Parodi Amaya

LSU Doctoral Dissertations

The work presented here has 3 goals: establish the need for novel neurostimulation waveform solutions through a literature review, develop a neurostimulation pulse generator, and verify the operation of the device for neurostimulation applications.

The literature review discusses the importance of stimulation waveforms on the outcomes of neurostimulation, and proposes new directions for neurostimulation research that would help in improving the reproducibility and comparability between studies.

The pulse generator circuit is then described that generates signals inspired by the shape of excitatory or inhibitory post-synaptic potentials (EPSP, IPSP). The circuit analytical equations are presented, and the effects of the circuit …

Development Of A Sonically Powered Biodegradable Nanogenerator For Bone Regeneration, Avi S. Patel

University Scholar Projects

Background: Reconstruction of bone fractures and defects remains a big challenge in orthopedic surgery. While regenerative engineering has advanced the field greatly using a combination of biomaterial scaffolds and stem cells, one matter of difficulty is inducing osteogenesis in these cells. Recent works have shown electricity’s ability to promote osteogenesis in stem cell lines when seeded in bone scaffolds; however, typical electrical stimulators are either (a) externally housed and require overcomplex percutaneous wires be connected to the implanted scaffold or (b) implanted non-degradable devices which contain toxic batteries and require invasive removal surgeries.

Objective: Here, we establish a biodegradable, piezoelectric …

Seeing Eye To Eye: A Machine Learning Approach To Automated Saccade Analysis, Maigh Attre

Honors Scholar Theses

Abnormal ocular motility is a common manifestation of many underlying pathologies particularly those that are neurological. Dynamics of saccades, when the eye rapidly changes its point of fixation, have been characterized for many neurological disorders including concussions, traumatic brain injuries (TBI), and Parkinson’s disease. However, widespread saccade analysis for diagnostic and research purposes requires the recognition of certain eye movement parameters. Key information such as velocity and duration must be determined from data based on a wide set of patients’ characteristics that may range in eye shapes and iris, hair and skin pigmentation [36]. Previous work on saccade analysis has …

Development Of A Myoelectric Detection Circuit Platform For Computer Interface Applications, Nickolas Andrew Butler

Master's Theses

Personal computers and portable electronics continue to rapidly advance and integrate into our lives as tools that facilitate efficient communication and interaction with the outside world. Now with a multitude of different devices available, personal computers are accessible to a wider audience than ever before. To continue to expand and reach new users, novel user interface technologies have been developed, such as touch input and gyroscopic motion, in which enhanced control fidelity can be achieved. For users with limited-to-no use of their hands, or for those who seek additional means to intuitively use and command a computer, novel sensory systems …

A Brain-Computer Interface For Closed-Loop Sensory Stimulation During Motor Training In Patients With Tetraplegia, Sarah Helen Thomas

Theses and Dissertations--Biomedical Engineering

Normal movement execution requires proper coupling of motor and sensory activation. An increasing body of literature supports the idea that incorporation of sensory stimulation into motor rehabilitation practices increases its effectiveness. Paired associative stimulation (PAS) studies, in which afferent and efferent pathways are activated in tandem, have brought attention to the importance of well-timed stimulation rather than non-associative (i.e., open-loop) activation. In patients with tetraplegia resulting from spinal cord injury (SCI), varying degrees of upper limb function may remain and could be harnessed for rehabilitation. Incorporating associative sensory stimulation coupled with self-paced motor training would be a means for supplementing …

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, …

Electrochemical And Spectroscopic Study Of Peptide-Template Melanins, Daniel Courter, Olivia Rossi, Zhen Tian

Honors Theses and Capstones

Melanins are organic polymers made up of 5,6-dihydroxyindole carboxylic acid (DHICA) and 5,6-dihydroxyindole (DHI). Biochemical systems synthesize melanins through a complex reaction pathway. Previous research exhibited that naturally-occurring melanins (NatMel) and their synthetic analogues (SynMel) can potentially serve as electrode materials for aqueous charge storage devices. Small surface area creates technical challenges for these melanins as charge storage materials. This research herein demonstrates that the structure of melanins can affect the charge storage capacities of monovalent Na⁺cations and divalent Mg²⁺ cations. 2-D sheet-like peptide melanins (PepMel) were synthesized into tripeptides consisting of aspartic acid (D), phenylalanine (F), …

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 …

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

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 …

Developing An Imaging Biomarker To Detect Aberrant Brain Connectivity In Individual Patients, Esther Cox

Master's Theses (2009 -)

Resting state functional MRI (rsfMRI) has been proven to be a valuable tool in clinical applications such as pre-surgical mapping, but there is not yet a functional and usable algorithm that can be used by physicians in a clinical setting to evaluate an individual patient for diseases and aberrant brain connectivity. If a physician wants to evaluate a patient in this way, the rsfMRI data must be looked at “by hand,” i.e. the physician must manually evaluate the data and identify the functional ICN’s and whether they are normal or aberrant. An algorithm that would automate this process and supplement …

Ultrasonic Power Transfer For Medical Implants, Kee S. Moon, Yusuf Ozturk, Sung Q. Lee, Woosub Youm, Guun Hwang, H. W. Park

Biomedical Engineering Western Regional Conference

Wireless power transmission is an attractive alternative to low-power biomedical implants to overcome the power limitation of the primary battery. In this paper, we are presenting an efficient ultrasonic wireless power transmission system for implantable medical devices. It is known that the ultrasonic wireless power transmission has a longer power transmission distance as well as free from electromagnetic interference and absorption in the human body. In this research, an ultrasonic resonance will be applied to improve the power transmission efficiency as well as the distance.

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 …

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

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 …

Structural-Functional Brain Connectivity Underlying Integrative Sensorimotor Function After Stroke, Benjamin Thomas Kalinosky

Dissertations (1934 -)

In this dissertation research project, we demonstrated the relationship between the structural and functional connections across the brain in stroke survivors. We used this information to predict arm function in stroke survivors, suggesting that the tools developed through this research will be useful for prescribing individualized rehabilitation strategies in people after stroke. Current clinical methods for rehabilitating sensorimotor function after stroke are not based on the locus of injury in the brain. Instead, therapies are generalized, treating symptoms such as weakness and spasticity. This results in outcomes that are highly variable, with severity of impairment immediately following stroke as the …

Closed-Loop Afferent Nerve Electrical Stimulation For Rehabilitation Of Hand Function In Subjects With Incomplete Spinal Cord Injury, Christopher J. Schildt

Theses and Dissertations--Biomedical Engineering

Peripheral nerve stimulation (PNS) is commonly used to promote use-dependent cortical plasticity for rehabilitation of motor function in spinal cord injury. Pairing transcranial magnetic stimulation (TMS) with PNS has been shown to increase motor evoked potentials most when the two stimuli are timed to arrive in the cortex simultaneously. This suggests that a mechanism of timing-dependent plasticity (TDP) may be a more effective method of promoting motor rehabilitation. The following thesis is the result of applying a brain-computer interface to apply PNS in closed-loop simultaneously to movement intention onset as measured by EEG of the sensorimotor cortex to test whether …

Quantification Of Blood Flow Velocity Using Color Sensing, Aditya Deepak Sanghani

Master's Theses

Blood flow velocity is an important parameter that can give information on several pathologies including atherosclerosis, glaucoma, Raynaud’s phenomenon, and ischemic stroke [2,5,6,10]. Present techniques of measuring blood flow velocity involve expensive procedures such as Doppler echocardiography, Doppler ultrasound, and magnetic resonance imaging [11,12]. They cost from $8500-$20000. It is desired to find a low-cost yet equally effective solution for measuring blood flow velocity. This thesis has a goal of creating a proof of concept device for measuring blood flow velocity.

Finger blood flow velocity is investigated in this project. The close proximity to the skin of the finger’s arteries …