Time-Frequency Analysis Applied to Autonomic Nervous System Activity in a Biofeedback Environment

The Autonomic Nervous System (ANS) is a subconscious system within the peripheral nervous system that controls such things as heart rate, respiration, baroreceptor control, sweating, and regulation of internal organs. Certain aspects of this system can be under conscious control given time and practices. The ANS may be further divided into two subsections, namely the Sympathetic (Fight or Flight) and Parasympathetic ( Rest and Digest) nervous system. These systems work symbiotically; however they have almost opposite effects on organs within the body. Within this project a compelling biofeedback game was built with a protocol whereby the users used their relaxation as a driving mechanism in order to open a locked door. This game was driven using the biometrics of Galvanic Skin Response (GSR) and Electroencephalogram (EEG) as a measurement of relaxation. In addition to this the additional biometric of Heart Rate (HR) was also taken. HR and GSR both have characteristics which show the interrelationship between sympathetic and parasympathetic activity. This thesis explored time-frequency algorithms in order to firstly turn a two dimensional signal into a three dimensional energy representation to reveal more information about the degree of which system predominated per unit time. From here a successful attempt was made to relate HR and GSR to one another in a time frequency domain. It was also shown that the alternation between sympathetic and parasympathetic could be observed in the cross time-frequency domain. This exploration was made using 16 test subjects playing the game

Augmented control of hands free voice prostheses

Laryngectomy patients often use an electrolarynx to facilitate speech following a tracheotomy. Devices of this type provide the most intelligible means of communication for tracheotomy patients. However, the electro-larynx has inherent drawbacks such as the buzzing monotonic sound emitted, the need for a free hand to operate the device, and the difficulty experienced by many tracheotomy patients in adapting to use it. The most effective means of addressing the shortcomings of existing electro-larynges is to provide the user with a hands-free facility. This allows the user to perform other manual tasks whilst speaking, or simply to communicate more effectively through body language. Hands-free devices do exist but require a considerable amount of patient training as they involve the use of the shoulder muscles to control pitch. Furthermore, they are not suitable for all patients as the hands-free is suitable only for users with a certain type of tracheotomy. Goldstein et al in 2004 [1] produced a working prototype of a hands-free device that employed electromyographic signals to activate the device. However, it was quite cumbersome in design and failed to alleviate the monotonous sound produced. The goal of this research is to research the implementation of a hands-free electrolarynx, using various activation methods including electromyographic signals to vary parameters of the output signal. Once a satisfactory system of initiation has been devised and tested, a method of pitch variation shall be developed

Improving Writing Quality of Capstone Reports

Abstract-Contributions: The main contribution is to share a series of practical methods that improve the writing quality of capstone reports. Background: The ability to write well is critical to the success of an engineering technology graduate. However, the evidence points to the fact that industries are disappointed with the quality of writing skills graduates demonstrate. Intended Outcomes: A faculty review of capstone reports showed little improvement in writing quality from the first course to the second in a two-semester capstone sequence. Therefore, the instructors explored what actions were needed to improve the writing quality of the capstone reports. Application Design: Several changes in the capstone courses were developed and implemented. The changes included 1) using instructional technology as a scaffolding to help frame the writing required for the course and 2) engaging students in iterative writing with feedback. Findings: The assessment data showed a significant improvement, at the 5% level. The iterative process of writing and rewriting the report, coupled with frequent meetings with faculty mentors, proved to be a powerful combination for improving the writing prowess of the students

Intelligibility of Electrolarynx Speech using a Novel Hands-Free Actuator

During voiced speech, the larynx provides quasi-periodic acoustic excitation of the vocal tract. In most electrolarynxes, mechanical vibrations are produced by a linear electromechanical actuator, the armature of which percusses against a metal or plastic plate at a frequency within the range of glottal excitation. In this paper, the intelligibility of speech produced using a novel hands-free actuator is compared to speech produced using a conventional electrolarynx. Two able-bodied speakers (one male, one female) performed a closed response test containing 28 monosyllabic words, once using a conventional electrolarynx and a second time using the novel design. The resulting audio recordings were randomized and replayed to ten listeners who recorded each word that they heard. The results show that the speech produced using the hands-free actuator was substantially more intelligible to the majority of listeners than that produced using the conventional electrolarynx. The new actuator has properties (size, weight, shape, cost) which lends itself as a suitable candidate for possible hands-free operation. This is one of the research ideals for the group and this test methodology presented as a means of testing intelligibility. This paper outlines the procedure for the possible testing of intelligibility of electrolarynx designs

Mid-Holocene Antarctic sea-ice increase driven by marine ice sheet retreat

© The Author(s), 2021. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Ashley, K. E., McKay, R., Etourneau, J., Jimenez-Espejo, F. J., Condron, A., Albot, A., Crosta, X., Riesselman, C., Seki, O., Mass, G., Golledge, N. R., Gasson, E., Lowry, D. P., Barrand, N. E., Johnson, K., Bertler, N., Escutia, C., Dunbar, R., & Bendle, J. A. Mid-Holocene Antarctic sea-ice increase driven by marine ice sheet retreat. Climate of the Past, 17(1), (2021): 1-19, https://doi.org/10.5194/cp-17-1-2021.Over recent decades Antarctic sea-ice extent has increased, alongside widespread ice shelf thinning and freshening of waters along the Antarctic margin. In contrast, Earth system models generally simulate a decrease in sea ice. Circulation of water masses beneath large-cavity ice shelves is not included in current Earth System models and may be a driver of this phenomena. We examine a Holocene sediment core off East Antarctica that records the Neoglacial transition, the last major baseline shift of Antarctic sea ice, and part of a late-Holocene global cooling trend. We provide a multi-proxy record of Holocene glacial meltwater input, sediment transport, and sea-ice variability. Our record, supported by high-resolution ocean modelling, shows that a rapid Antarctic sea-ice increase during the mid-Holocene (∼ 4.5 ka) occurred against a backdrop of increasing glacial meltwater input and gradual climate warming. We suggest that mid-Holocene ice shelf cavity expansion led to cooling of surface waters and sea-ice growth that slowed basal ice shelf melting. Incorporating this feedback mechanism into global climate models will be important for future projections of Antarctic changes.This research has been supported by the Natural Environment Research Council (CENTA PhD; NE/L002493/1 and Standard Grant Ne/I00646X/1), Japanese Society for the Promotion of Science (JSPS/FF2/60 no. L-11523), NZ Marsden Fund (grant nos. 18-VUW-089 and 15-VUW-131), NSF (grant nos. PLR-1443347 and ACI-1548562), the U.S. Dept. of Energy (grant no. DE-SC0016105), ERC (StG ICEPROXY, 203441; ANR CLIMICE, FP7 Past4Future, 243908), L'Oréal-UNESCO New Zealand For Women in Science Fellowship, University of Otago Research Grant, the IODP U.S. Science Support Program, Spanish Ministry of Science and Innovation (grant no. CTM2017-89711-C2-1-P), and the European Union (FEDER)

The processing and impact of dissolved riverine nitrogen in the Arctic Ocean

© The Author(s), 2011. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Estuaries and Coasts 35 (2012): 401-415, doi:10.1007/s12237-011-9417-3.Although the Arctic Ocean is the most riverine-influenced of all of the world’s oceans, the importance of terrigenous nutrients in this environment is poorly understood. This study couples estimates of circumpolar riverine nutrient fluxes from the PARTNERS (Pan-Arctic River Transport of Nutrients, Organic Matter, and Suspended Sediments) Project with a regionally configured version of the MIT general circulation model to develop estimates of the distribution and availability of dissolved riverine N in the Arctic Ocean, assess its importance for primary production, and compare these estimates to potential bacterial production fueled by riverine C. Because riverine dissolved organic nitrogen is remineralized slowly, riverine N is available for uptake well into the open ocean. Despite this, we estimate that even when recycling is considered, riverine N may support 0.5–1.5 Tmol C year−1 of primary production, a small proportion of total Arctic Ocean photosynthesis. Rapid uptake of dissolved inorganic nitrogen coupled with relatively high rates of dissolved organic nitrogen regeneration in N-limited nearshore regions, however, leads to potential localized rates of riverine-supported photosynthesis that represent a substantial proportion of nearshore production.Funding for this work was provided through NSFOPP- 0229302 and NSF-OPP-0732985.Support to SET was additionally provided by an NSERC Postdoctoral Fellowship

Pools, transformations, and sources of P in high-elevation soils: Implications for nutrient transfer to Sierra Nevada lakes

In high-elevation lakes of the Sierra Nevada (California), increases in P supply have been inferred from shifts in P to N limitation. To examine factors possibly leading to changes in P supply, we measured pools and transformations in soil P, and developed a long-term mass balance to estimate the contribution of parent material weathering to soil P stocks. Common Sierra Nevada soils were found to not be P-deficient and to be retentive of P due to the influence of Fe- and Al-oxides. Total P averaged 867μgPg-1 in the top 10cm of soil (O and A horizons) and 597μgPg-1 in the 10-60cm depth (B horizons), of which 70% in A horizons and 60% in B horizons was freely exchangeable or associated with Fe and Al. Weathering of parent material explained 69% of the P found in soils and lost from the catchment since deglaciation, implying that long-term atmospheric P deposition (0.02kgha-1yr-1) represented the balance of P inputs (31%) during the past 10,000years of soil development. During spring snowmelt ~27% of the total soil P was transferred between organic and inorganic pools; average inorganic P pools decreased by 232μgPg-1, while organic P pools increased by 242μgPg-1. Microbial biomass P was highest during winter and decreased six-fold to a minimum in the fall. Interactions between hydrology and biological processes strongly influence the rate of P transfer from catchment soils to lakes. © 2013 Elsevier B.V

Wheel and Shaft

Patent for a wheel and shaft designed for use in drilling oil and gas wells

Augmented Control of a Hands-Free Electrolarynx

During voiced speech, the larynx acts as the sound source, providing a quasi-periodic excitation of the vocal tract. Following a total laryngectomy, some people speak using an electrolarynx which employs an electromechanical actuator to perform the excitatory function of the absent larynx. Drawbacks of conventional electrolarynx designs include the monotonic sound emitted, the need for a free-hand to operate the device, and the difficulty experienced by many laryngectomees in adapting to its use. One improvement to the electrolarynx, which clinicians and users frequently suggest, is the provision of a convenient hands-free control facility. This would allow more natural use of body language, as well as enabling the user to perform other manual tasks whilst speaking. An additional enhancement is the redevelopment of the devices\u27 actuator to remove the self-radiated buzzing sound which is emitted during operation. The overall goal of this research is to investigate the implementation of a more natural sounding, hands-free electrolarynx, with an activation method which uses accelerometers that are placed on the chest and abdomen to detect torso based breathing prior to the initiation of speech. Results illustrate from intelligibility tests carried out that the speech produced using our novel actuator is substantially more intelligible to all the listeners than that produced using the conventional electrolarynx. Also, the abrupt change in breathing pattern which occurs at the onset of speech is clearly observable in signals recorded by the accelerometers, facilitating a possible automatic activation of an electro-larynx which will be investigated further in user trials