Matching Items (20)

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Accurate Articulation of /r/: Relationships between Signal Processing Analysis of Speech and Ultrasound Images of the Tongue

Description

Research on /r/ production previously used formant analysis as the primary acoustic analysis, with particular focus on the low third formant in the speech signal. Prior imaging of speech used

Research on /r/ production previously used formant analysis as the primary acoustic analysis, with particular focus on the low third formant in the speech signal. Prior imaging of speech used X-Ray, MRI, and electromagnetic midsagittal articulometer systems. More recently, the signal processing technique of Mel-log spectral plots has been used to study /r/ production in children and female adults. Ultrasound imaging of the tongue also has been used to image the tongue during speech production in both clinical and research settings. The current study attempts to describe /r/ production in three different allophonic contexts; vocalic, prevocalic, and postvocalic positions. Ultrasound analysis, formant analysis, Mel-log spectral plots, and /r/ duration were measured for /r/ production in 29 adult speakers (10 male, 19 female). A possible relationship between these variables was also explored. Results showed that the amount of superior constriction in the postvocalic /r/ allophone was significantly lower than the other /r/ allophones. Formant two was significantly lower and the distance between formant two and three was significantly higher for the prevocalic /r/ allophone. Vocalic /r/ had the longest average duration, while prevocalic /r/ had the shortest duration. Signal processing results revealed candidate Mel-bin values for accurate /r/ production for each allophone of /r/. The results indicate that allophones of /r/ can be distinguished based the different analyses. However, relationships between these analyses are still unclear. Future research is needed in order to gather more data on /r/ acoustics and articulation in order to find possible relationships between the analyses for /r/ production.

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  • 2017-05

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Ultrasound Sensitive Injectable Materials

Description

In an embolization therapy, a material is injected into a vessel to block blood flow. While this therapy is useful in starving cancerous cells it can be dangerous, with some

In an embolization therapy, a material is injected into a vessel to block blood flow. While this therapy is useful in starving cancerous cells it can be dangerous, with some blockades in the brain dislodging and causing strokes or blindness. Currently, embolic materials on the market such as metal coils, balloons, and liquid embolic agents do not have a quick removal procedure. An ultrasound cleavable material could be removed in an emergency situation without invasive surgery. The primary goal of this research is to design and synthesize a polymer that can be broken down by high intensity focused ultrasound (HIFU). Initially, we have tested the ultrasound sensitive qualities on PPODA-QT hydrogel, a common embolic agent, but the gel showed no physical change after HIFU exposure. It is theorized that PNIPAAm combined with HIFU sensitive monomers can develop a temperature and ultrasound sensitive embolic agent. In our studies, poly(NIPAAm-co-tBa) had a slight lower critical solution temperature (LCST) change of about 2˚C from before to after HIFU while the study with poly(NIPAAm-co-ACL-BME) and PPODA-QT showed no change in LCST.

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Date Created
  • 2020-05

Development and Assessment of Two Novel Pitting Designs for Increased Needle Visibility under Ultrasound

Description

Nerve endings are particularly difficult to target during peripheral nerve block (PNB) procedures, so ultrasound-guided needles are of immense importance to guarantee safe and efficient delivery of the anesthetic to

Nerve endings are particularly difficult to target during peripheral nerve block (PNB) procedures, so ultrasound-guided needles are of immense importance to guarantee safe and efficient delivery of the anesthetic to the target nerve. Despite significant progress in needle visualization with ultrasound imaging, there are still several factors that lead to poor needle visibility, the main factor being insertion angle. Introducing cavities and holes in the needle at specific intervals through pitting corrosion may alter the ultrasonic feedback from the sensor, thereby resulting in improved clarity of the reconstructed image. The purpose of this experiment is to investigate the effectiveness of two novel pitting designs on the needle’s visibility under ultrasound. Two different designs and two depths of cut are tested in a 22 factorial that is blocked by insertion angle: a uniform and a non-uniform design. Needles were cut using a Plain Jane and Igor laser cutter and imaged using a GE Logig e BT12 ultrasound imaging machine. Images were compared visually and objectively by using a tool in Photoshop to calculate the luminosity of the needle. Two videos were also taken capturing the difficulty of imaging surgical needles. Results showed that pitting had a major impact on needle visibility at 30° and a marginal impact at 0°. The videos supported these results as it was considerably more difficult to locate the control needle than the experimental needle. This suggests the probe must be in a specific plane with the control needle for it to be visible while the experimental needle is much more lenient. Results from the two depths of cuts showed similar results in that the designs which were cut twice were more visible than their counterparts at 30°. The study showed that pitting has positive effects on needle visibility; it improves visibility by increasing the luminescence of the needle and by decreasing its sensitivity to probe position.

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  • 2016-05

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Assessing the Navigational Abilities of an Acoustically Active Cannula

Description

The purpose of this thesis experiment was to design and create an Acoustically Active Cannula (AAC), which is furnished by a piezoelectric crystal placed at its tip that produces an

The purpose of this thesis experiment was to design and create an Acoustically Active Cannula (AAC), which is furnished by a piezoelectric crystal placed at its tip that produces an acoustic navigation signal. I tested the functionality of the cannula in vitro and demonstrated its navigational abilities in vivo in anesthetized pigs. This experiment was based upon ultrasound science and technology, and thus some practical experience with conventional (B-mode) and Doppler ultrasound was achieved as well. The results of bench and experimental animal studies indicated proper functionality of the AAC for identification and spatial navigation of its tip with color Doppler ultrasound imaging.

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Date Created
  • 2018-05

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Design and Development of Injectable, Wireless, Sub-Millimeter Neurostimulators

Description

An improved system for wireless neurostimulation was investigated through the design and development of sub-millimeter piezoelectric devices. The devices build on prior work in the lab, which was limited by

An improved system for wireless neurostimulation was investigated through the design and development of sub-millimeter piezoelectric devices. The devices build on prior work in the lab, which was limited by device size and required surgical implantation. A method of manufacturing sub-mm devices was developed, and utilized to construct this new design. The device frequency response was characterized and its resonant modes and output voltages determined through a Fast Fourier Transform. The fundamental thickness mode frequency was found to be 15.4MHz with a corresponding 10.25mV amplitude, and a longitudinal resonant frequency of 3.1Mhz with a corresponding 2.2mV amplitude across a 50Ω resistor. The high miniaturization of the device holds promise for future work for creating an injectable, wireless system for the treatment of neurological disorders.

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Date Created
  • 2018-05

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The Relationship of Muscle Thickness and Pennation Angle to Muscle Function by Ultrasound Imaging

Description

This purpose of this study was to develop reliable methods for ultrasound measurements of skeletal muscle architecture, and to identify which specific quadriceps measurements most closely relate to peak isometric

This purpose of this study was to develop reliable methods for ultrasound measurements of skeletal muscle architecture, and to identify which specific quadriceps measurements most closely relate to peak isometric torque of the leg extensors. These data were obtained as part of a larger research study and consist of 9 total subjects (4 males, 5 females; age (30.6 ± 13.6yr). Ultrasound images for muscle thickness and pennation angle were obtained for each subject during two separate testing days (separated by 5-10 days). Images were acquired at various anatomical sites of the quadriceps and each image was analyzed using Image J software. Quadriceps muscles assessed for muscle thickness and pennation angle included the vastus lateralis (VL), and vastus intermedius (VI), while rectus femoris (RF) was assessed only for muscle thickness. Peak isometric torque measurements were obtained at 60 degrees of knee angle for knee extension using an isokinetic dynamometer. Results show that the methods chosen for ultrasound measurement produced reliable inter-day results for muscle thickness and pennation angle. VL muscle thickness and pennation angle obtained at the lateral site corresponding to 39% of leg length was highly related to peak isometric torque for knee extension. The results of this study identify specific measurement sites that are related to muscle function. In addition, these data further validate that ultrasound measurement is reliable to measure muscle thickness and pennation angle in skeletal muscle.

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Date Created
  • 2016-05

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Ultrasound Imaging of Swallowing Subsequent to Feeding and Myofunctional Intervention

Description

The purpose of this study was to examine swallowing patterns using ultrasound technology subsequent to the implementation of two therapeutic interventions. Baseline swallow patterns were compared to swallows after implementation

The purpose of this study was to examine swallowing patterns using ultrasound technology subsequent to the implementation of two therapeutic interventions. Baseline swallow patterns were compared to swallows after implementation of therapeutic interventions common in both feeding therapy (FT) and orofacial myofunctional therapy (OMT). The interventions consist of stimulation of the tongue by z-vibe and tongue pops. Changes in swallowing patterns are described, and similarities of interventions across the two professions are discussed. Ultrasound research in the realm of swallowing is sparse despite having potential clinical application in both professions. In using ultrasound, this study outlines a protocol for utilization of a hand-held probe and reinforces a particular protocol described in the literature. Real-time ultrasound recordings of swallows for 19 adult female subjects were made. Participants with orofacial myofunctional disorder are compared to a group with typical swallowing and differences in swallowing patterns are described. Three stages of the oral phase of the swallow were assigned based on ultrasonic observation of the tongue shape. Analysis involves total duration of the swallow, duration of the three stages in relation to the total duration of the swallow, and the number of swallows required for the bolus to be cleared from the oral cavity. No significant effects of either intervention were found. Swallowing patterns showed a general trend to become faster in total duration subsequent to each intervention. An unexpected finding showed significant changes in the relationship between the bolus preparation stage and the bolus transportation stage when comparing the group classified as having a single swallow and the group classified as having multiple swallows.

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Date Created
  • 2016-05

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Ultrasound Based Predictive Maintenance

Description

The basis of this project was to analyze the potential cost savings derived from the implementation of an ultrasonic flaw detector for gas pipes in factories. The group began by

The basis of this project was to analyze the potential cost savings derived from the implementation of an ultrasonic flaw detector for gas pipes in factories. The group began by researching the market of the Industrial Internet of Things. IIoT is a very attractive market for investment, as connected technologies are become both more advanced and more affordable. Factory automation also saves costs of human capital, maintenance, and bad product cost as well as safety. After doing this preliminary research, the group continued by identifying potential solutions to current shortcomings of the manufacturing status quo. After narrowing down the options, the ultrasonic flaw detector appeared to have the highest potential for success in Company X's factories. The group began doing research on what physical components would go into this solution. They found pricing for all of the various parts of such a device as well as estimated labor, maintenance, and implementation costs. After estimating these costs, the team began the construction of a detailed financial model to generate the hypothetical net present value of such a tool. After presenting two times to a panel of Company X employees, the group decided to focus only on cost savings for Company X, and not the potential revenues of selling the whole solution. They ran a sensitivity analysis on all of the factors that contributed to the NPV of the project, and discovered that the estimated percentage of scrapped product resulting from gas leaks and the percentage of gas lost to leaks contributed the most to the NPV.

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Date Created
  • 2017-05

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Ultrasound on the Central Nervous System

Description

Ultrasound is a sound wave that produces acoustic pressure and is most commonly known as a noninvasive technique for bodily imaging. However, high-intensity focused ultrasound can be used for noninvasive

Ultrasound is a sound wave that produces acoustic pressure and is most commonly known as a noninvasive technique for bodily imaging. However, high-intensity focused ultrasound can be used for noninvasive physiotherapy. An example of this the treatment of tumors in the kidneys, as the sound waves of HIFU interacts with tissues in the body. For this thesis, the necessary parameters for ultrasonic stimulation of the central nervous system in rats were characterized.

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Date Created
  • 2013-05

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Test Instrument, Bolus size, Multiple Swallows and Ultrasound in the Evaluation of Oral-Stage Swallow

Description

A previous study identified a subset of participants who required multiple swallows to clear a single bolus (Weinhold & McKay, 2017). Presence of multiple swallows was positively correlated with orofacial

A previous study identified a subset of participants who required multiple swallows to clear a single bolus (Weinhold & McKay, 2017). Presence of multiple swallows was positively correlated with orofacial myofunctional disorder (OMD), suggesting that multiple swallows might be a potential screening marker for OMD. Since bolus size was not controlled in the study, reviewers questioned whether multiple swallows might have been a consequence of larger bolus size. In 2018, Pennington and Weinhold replicated this study by using a consistent 5ml bolus and revealed a similar correlation between OMD and multiple swallows. However, the test instrument used in that study to identify OMD yielded an OMD incidence of 60%. Accordingly, a new test instrument was developed to increase specificity of scoring for future studies. The new instrument identified 30% of participants as having OMD, which is more in line with the literature. The current study replicated Weinhold & McKay (2017) by utilizing the new test instrument as well as a predetermined average sip size for each participant. Utilizing both a controlled bolus of 5ml, and a participant-specific bolus size failed to eliminate multiple swallows. Linear regression revealed no significant relationship between size of bolus and number of swallows for either study; therefore, the hypothesis that the size of the unmeasured boluses in Weinhold & McKay caused differences in number of swallows was rejected. The suggestion that multiple swallows are indicative of OMD was strengthened, prompting further investigation into the relationship between number of swallows per bolus and OMD. Ultrasound images of three stages of the oral swallow were compared for the OMD and non-OMD groups. No statistical differences were noted in tongue constriction, which did not support our hypothesis that the OMD participants would display less constriction. However, baseline tongue position of /𝑎/ for participants with OMD was significantly lower than the baseline of participants without OMD. Pertinence of these findings relative to the oral stages of the swallow are addressed, as well as implications of oral stage dysfunction in general.

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Date Created
  • 2019-05