Telephones are an integral part of everyday life in today's society. It is well known that hearing impaired people have difficulty understanding speech on the telephone. The ability to use the telephone is commonly reported as one of the many benefits of cochlear implantation. Assessment for a cochlear implant (CI) includes a variety of aspects related to communication and hearing ability. Included in the case history, mention is made whether the person can use the telephone. The purpose of the present study was firstly to identify if the inability to use the telephone could be used a predictor for suitability for a cochlear implant. It was also purposed to determine if telephone ability could be assessed by self-reported measures. The participants were 13 severe to profoundly hearing impaired people who had previously undergone candidacy assessment for a cochlear implant. Each participant was evaluated on their use and understanding of speech on the telephone. Participants were separated into two groups: those who were candidates for a cochlear implant and those who were not. Speech perception testing was evaluated using a recording of CUNY sentences on the telephone. Results indicated that cochlear implant candidates correctly perceived a significantly lower number of words on the telephone than non-candidates. Use of the telephone was evaluated using a 51-item questionnaire. Results indicated that there was no significant difference in self-reported use of the telephone between cochlear implant candidates and non-candidates. The differences in speech perception understanding on the telephone were most likely due to the overall better hearing levels of the non-candidates. The clinical implications of the present study are considered.

Cette thèse porte sur la perception visuelle, auditive et audiovisuelle des voyelles nasales [ɑ̃] (« lent »),[ɔ̃] (« long ») et [ɛ̃] (« lin ») par des adultes devenus sourds, implantés cochléaires et implantés dutronc cérébral. L’étude sur la perception visuelle des voyelles, auprès de 22 adultes devenus sourds,redéfinit les sosies labiaux des voyelles nasales et propose une mise à jour de la classification desvisèmes. Trois études sur l’identification auditive des voyelles nasales auprès de 82, 15 et 10 adultesimplantés cochléaires mettent en évidence leur difficulté à reconnaitre les trois voyelles nasales, qu’ilsperçoivent comme des voyelles orales. Les analyses acoustiques et perceptives suggèrent que lesadultes implantés cochléaires s’appuient sur les informations fréquentielles des deux premiers picsspectraux mais négligent les informations d’intensité relative de ces pics. D’après l’étude menéeauprès de 13 adultes implantés du tronc cérébral, des informations acoustiques linguistiques sonttransmises par l’implant du tronc cérébral mais la fusion entre les informations auditives et visuellespourrait être optimisée pour l’identification des voyelles. Enfin, une enquête auprès de 179orthophonistes pointe le besoin d’une information sur la définition phonétique articulatoire actualiséedes voyelles [ɑ̃] et [ɛ̃]. / This thesis focuses on the visual, auditory and auditory-visual perception of french nasal vowels [ɑ̃](« lent »), [ɔ̃] (« long ») and [ɛ̃] (« lin ») by Cochlear Implant (CI) and Auditory Brainstem Implant(ABI) adults users. The study on visual perception of vowels, with 22 deafened adults, redefines thelip configuration of french nasal vowels and provides an update of the classification of vocalic visualphonemes. Three studies on auditory identification of nasal vowels with 82, 15 and 10 CI usershighlight their difficulty in recognizing the three nasal vowels, which they perceive as oral vowels.Acoustic and perceptual analyzes suggest that adults with CI rely on frequency informations of thefirst two spectral peaks but miss the informations of relative intensity of these peaks. The study with13 ABI users show that some linguistic acoustic cues are transmitted by the ABI but the fusion ofauditory and visual features could be optimized for the identification of vowels. Finally, a survey of179 Speech Language and Hearing Therapists show the need of an update on the phonetic articulationof french nasal vowels [ɑ̃] and [ɛ̃].

Disruption of the scapholunate ligament can result in significant immediate and long-term disability. Of the available current acute and subacute treatment strategies for this disorder, the use of a solid screw to stabilize the scapholunate relationship has been proposed. However, subsequent carpal bone loss is an inherent risk to this technique. The goal of this study was to design a flexible orthopedic screw that can be placed between the scaphoid and lunate to restore more normal biomechanics without the risk of osteolysis. Several ideas were generated during the course of the study to create a moveable section in a bone screw implant. Designs that met the specifications and were promising from the manufacturing point of view were tested using finite element analysis. Some designs were prototyped and one of them was tested using a cadaver wrist. Every design concept revealed some positive and negative features in terms of manufacturing and functionality. It is promising in terms of fulfilling the design requirements, but prototyping the design was very difficult. In conclusion, it can be said that the invented flexible screw techniques are sufficient to hold the scaphoid and lunate together after the scapholunate ligament injury, to restore more normal wrist biomechanics.

M. Pharm., Faculty of Health Sciences, University of the Witwatersrand, 2009 / Parkinson's disease, primarily defined as the depletion of dopaminergic neurons in the subtantia nigra of the brain, gives rise to severely debilitating motor symptoms. The pharmacological gold standard treatment for the disease, Levodopa , holds great limitations yet still remains the most effective treatment for the disease for the last 40 years. There has been research into novel drug delivery systems for the treatment of the disease that include the development of implantable devices however none have been introduced onto the market. As the neurodegenerative disorder ravages the younger-aged population so the urgency for the effective chronic treatment of the disease escalates. The field of nanotechnology brings promise for the targeted delivery of drugs which is highly sought after in the treatment of central nervous system disorders. A nano-enabled scaffold device (NESD) incorporating dopamine nanoparticles into a polymeric scaffold for implantation into the brain parenchyma may be able to address and overcome the limitations of the current treatment for Parkinson's disease. Investigations performed cellulose acetate phthalate dopamine-loaded nanoparticles, employing an adopted emulsification-diffusion approach, produced particles with a notably high drug entrapment efficiency (63.05±0.354%) and desirable controlled drug release profiles (16.23% in 24hr). The employment of an experimental design, namely the Box-Behnken design, allowed for the attainment of optimized nanoparticles with high zeta potentials (.34.00mV), minimal particle size (197.20nm) and extended mean dissolution times (40.96). Barium chloride was employed to crosslink calcium-alginate scaffolds formulated in an adopted freeze-drying approach. Highly resilient (63.58±5.13) and porous structures (pore sizes of 100-400μm) were developed. A statistical approach employing the Box- Behnken design resulted in the formulation of a candidate barium-alginate scaffold displaying maximum matrix resilience (82.46%) and minimal matrix erosion (18.23%) over in 30 days. In addition, dopamine-loaded nanoparticles were dispersed within the scaffold that formed the NESD with the desired drug release profiles (5.12% in 168hr). Nanosystems of levodopa, nicotine and dopamine nanofibers were preliminary investigated. Drug release profiles for levodopa (4.21%: in 75hr), nicotine (0.42% in 24hrs) and drug entrapment efficiency for the polymeric nanofibers (75-85%) as well as data from scanning electron microscopy, zetasize analysis and drug release studies proved that these systems hold potential for the treatment of the disease and therefore require further investigation. Ex vivo cytotoxic studies carried out on the NESD and it's separate entities proved that the NESD was biocompatible with the white blood (70-80% cell viability in 24hr) and carcinomic brain cells (25% cell viability in 48hr) despite literature reports of dopamine being highly toxic in vivo. Extensive in vivo studies resulted in the development of a protocol for the surgical implantation of the NESD in the parenchyma of the frontal lobe of the rat brain. Scanning electron microscope images showed the gradual bioerosion (26% in 30 days) of the NESD while histological findings of the brain tissue proved clinically insignificant (absence of ischemia or chronic inflammation). Ultra Liquid Performance Chromatography revealed higher concentrations of dopamine in the CSF of rats which received brain implants of the NESD (28%) than in those administered the oral preparation, Sinemet (0.000012%) in 3 days.

Hearing loss is a common impairment or disability for human beings, and is impacting an increasing amount of people, augmented by the growing aging population around the globe. Cochlear implantation, as one of the most effective ways to restore hearing, can only applied to profoundly deaf patients at the moment. In order to expand the group of people who can benefit from cochlear implantation to those with less severe hearing loss, endeavours need to be made to best preserve residual hearing and minimise trauma induced during cochlear implantation surgery. In this thesis, the disturbance induced in the cochlea, i.e. the acoustic and mechanical energy transmitted into the cochlea, during cochleostomy drilling is studied - as well as establishing a comparison between a manually guided conventional technique and a manually supported tissue guided robotic drilling technique. The results show that by changing surgical techniques and how they are applied can have a significant impact on levels of disturbance induced - robotic-aided approach induced lower level of equivalent SPL for up to 86% of the time and can be as much as 39 dB lower than that generated by conventional surgical drilling. This work is timely because trauma is an important consideration to clinicians and health care providers. Cochleostomy is one of the major and most disruptive surgical process during cochlear implantation. With the increasing amount of cochlear implant electrode array designs that are shorter and less intrusive, and the increasing demand of electric-acoustic stimulation via cochlear implant to better resemble the human auditory system, the approach to reduce disruption during cochleostomy drilling is highly relevant to the progression in the hearing care industry and the benefits of the growing hearing impairment community.

This thesis is to research connection process of multi-level conductor in integration circuits (ICs) manufacture technology. For the sake of sub-micro ICs which is gazed by people in the future, device¡¦s dimension have to be scaled down unceasingly; besides, the design of conductor connection of multi-level metal is also to be adopted for ULSI technology. However, the number of metal connection layer is increasing as well as the distance between wires is shorter and shorter, which leads to the fact that the RC delay time of metal interconnection is the primary reason of limiting the speed of semiconductor device while electronic signal is delivered among metal interconnection. In order to lower delay time of signal propagation, there are two parts in the following: In the aspect of lowering resistance, we substitute copper (resistance is 1.7£g£[-cm) at present for aluminum (resistance is 2.7£g£[-cm ) in the past so as to make copper be the wire for interconnection system. Furthermore, the scaled down device not only increase the current density of the wire but also increase the severity of electromigration inside the wire. Copper atoms are so heavier than aluminum atoms that copper atoms can restrain electromigration appropriately. In the aspect of decreasing capacitance, we will develop low dielectric constant (low-k). But copper with Damascene manufacture under the conditions of external operation such as temperature and electric field give rise to the fact that Cu diffuses into low-k material so easily that copper and low-k interact, which deteriorates the characteristic of the material¡Braises the leakage current and leads to the breakdown of the dielectric material. Therefore, it must be an important topic for study that we search for the dielectric barrier material with the characteristic against copper diffusion under the demand coinciding with integration process compatibility. At present, because of the material film called silicon carbide with low dielectric constant (k=4~6) attracts a lot of people¡¦s eyes deeply, it can applied to dielectric barrier technology to replace traditional dielectric barrier silicon nitride with high dielectric constant (k~8) for the purpose of alleviating delay time of the wire system. This thesis will discuss fundamental characteristics of silicon carbide film and some problems during the integration process. For instance, the impacts on silicon carbide under the conditions of fluorine plasma and thermal treatment; furthermore, this thesis will research the electric problems from the integration of low-k dielectric barrier and copper wire as well as probes into mechanism of leakage current.

Many cochlear implant (CI) recipients report the sound quality of their devices to be poor, for listening to music. The latest MED-EL speech processing strategy, Fine Structure Processing (FSP), aims to improve sound quality by encoding some of the low-frequency fine structure (FS) information. The goals of this study were twofold. The first was to develop a music quality rating test battery (MQRTB) for the New Zealand and Australian populations using commercially available songs. The second was to pilot test the MQRTB in a study comparing the MED-EL speech processing strategies FSP and High Definition Continuous Interleaved Sampling (HDCIS) for music appreciation. The research questions for the second part of this study were: (1) Does familiarity with a speech processing strategy affect musical quality ratings?; (2) Do CI recipients notice a significant difference between FSP and HDCIS when listening to music and if so, what aspects of the sound are different?; (3) Does song familiarity affect the quality ratings of music in CI recipients?; (4) Does music genre affect the quality ratings of music in CI recipients? The MQRTB used visual analogue scales for the attributes of pleasantness, naturalness, richness, fullness, sharpness, and roughness while listening to a home stereo. The scales were displayed on a computer touchscreen with the stimuli being presented via a home stereo system. There were ten songs in the MQRTB; a familiar and obscure song from each of the following genres: classical, modern, country and western, and common (such as a national anthem or iconic melody) genres, as well as two of the participant’s favourite songs. Five post-lingually deafened MED-EL SonataTI100 or PulsarCI100 CI recipients using the FSP strategy took part in the FSP versus HDCIS comparison study. Each participant spent three weeks acclimatising to either FSP or HDCIS before completing speech perception testing and the MQRTB task. Following this the participants were switched to the other speech processing strategy to acclimatise to for a further three weeks before re-assessment with the second strategy. At the conclusion of the study, the participants’ speech processors were returned to the pre-study settings. The results of the study showed an effect of acclimatisation on music quality ratings; when the participants were acclimatised to FSP, the group tended to prefer FSP; however, when acclimatised to HDCIS, the participants did not prefer HDCIS. As a group they rated FSP to sound closer to ‘what they would like music to sound like’ than HDCIS, and that HDCIS sounded significantly sharper and rougher than FSP. This suggested that music appreciation was better with FSP, but participants needed to be acclimatised to the strategy first. No effect of familiarity or genre was observed in the averaged group data, however, effects for some individuals were noted. Overall it would appear that FSP may improve music sound quality for some MED-EL CI recipients, however, it does not solve this issue. The MQRTB was also shown to be an effective tool to assess some aspects of music sound quality.

Cette thèse porte sur la perception visuelle, auditive et audiovisuelle des voyelles nasales [ɑ̃] (« lent »),[ɔ̃] (« long ») et [ɛ̃] (« lin ») par des adultes devenus sourds, implantés cochléaires et implantés dutronc cérébral. L’étude sur la perception visuelle des voyelles, auprès de 22 adultes devenus sourds,redéfinit les sosies labiaux des voyelles nasales et propose une mise à jour de la classification desvisèmes. Trois études sur l’identification auditive des voyelles nasales auprès de 82, 15 et 10 adultesimplantés cochléaires mettent en évidence leur difficulté à reconnaitre les trois voyelles nasales, qu’ilsperçoivent comme des voyelles orales. Les analyses acoustiques et perceptives suggèrent que lesadultes implantés cochléaires s’appuient sur les informations fréquentielles des deux premiers picsspectraux mais négligent les informations d’intensité relative de ces pics. D’après l’étude menéeauprès de 13 adultes implantés du tronc cérébral, des informations acoustiques linguistiques sonttransmises par l’implant du tronc cérébral mais la fusion entre les informations auditives et visuellespourrait être optimisée pour l’identification des voyelles. Enfin, une enquête auprès de 179orthophonistes pointe le besoin d’une information sur la définition phonétique articulatoire actualiséedes voyelles [ɑ̃] et [ɛ̃]. / This thesis focuses on the visual, auditory and auditory-visual perception of french nasal vowels [ɑ̃](« lent »), [ɔ̃] (« long ») and [ɛ̃] (« lin ») by Cochlear Implant (CI) and Auditory Brainstem Implant(ABI) adults users. The study on visual perception of vowels, with 22 deafened adults, redefines thelip configuration of french nasal vowels and provides an update of the classification of vocalic visualphonemes. Three studies on auditory identification of nasal vowels with 82, 15 and 10 CI usershighlight their difficulty in recognizing the three nasal vowels, which they perceive as oral vowels.Acoustic and perceptual analyzes suggest that adults with CI rely on frequency informations of thefirst two spectral peaks but miss the informations of relative intensity of these peaks. The study with13 ABI users show that some linguistic acoustic cues are transmitted by the ABI but the fusion ofauditory and visual features could be optimized for the identification of vowels. Finally, a survey of179 Speech Language and Hearing Therapists show the need of an update on the phonetic articulationof french nasal vowels [ɑ̃] and [ɛ̃].

Facial implants are becoming more common in America and across the world. In the United States last year, over 260,000 augmentation and reconstruction surgeries were performed on facial cartilage areas, while over two million soft tissue fillers were administered. The current implants on the market, though, are deficient in three major areas: they are too rigid, susceptible to migration, and require a large incision. Alternatively, dermal fillers lack shape and biodegrade too quickly. Poly(vinyl) alcohol (PVA) cryogel is a promising hydrogel alternative due to its softness, durable nature and ease of cast molding. While biocompatible, it does not elicit a fibrous response with firm adhesion and could migrate. The goal of this study is to develop a biodurable implant material that has soft-tissue elasticity, pores for adhesion, and swelling for small incisions. In this research, multiple porosity inducing methods are applied to PVA cryogel. These include a casting PVA cryogel over a porogen then leaching it in a solvent, a gaseous exothermic reaction, creating composites with biodegradable components, as well as using molds to alter the surface texture. Once created, the samples then underwent a series of tests to determine their mechanical properties which include elasticity, tensile strength, elongation, tear strength, pore size, and porosity. Swelling ratio of nonporous PVA cryogel was also considered. Porous PVA cryogel made with a high PVA weight percentage (30%) showed equivalent mechanical properties to that of cartilage. Porous PVA cryogel manufactured with a lower weight percent (10% and 20%) were shown to have similar elastic properties to that of adipose tissue. The surface texture methods, gas method, casting and leaching method, and composites made with CaPO4 and chitosan were all shown to create pores large enough for ingrowth. Samples created with a porosity large enough to encourage ingrowth include the gas method, casting and leaching method, and the CaPO4 composites. The swelling ratio was shown to increase as the weight percentage of PVA in the samples decreased. These quantified characteristics can be used to select the appropriate porous PVA cryogel required for a range of applications including facial implants.

Telephones are an integral part of everyday life in today's society. It is well known that hearing impaired people have difficulty understanding speech on the telephone. The ability to use the telephone is commonly reported as one of the many benefits of cochlear implantation. Assessment for a cochlear implant (CI) includes a variety of aspects related to communication and hearing ability. Included in the case history, mention is made whether the person can use the telephone. The purpose of the present study was firstly to identify if the inability to use the telephone could be used a predictor for suitability for a cochlear implant. It was also purposed to determine if telephone ability could be assessed by self-reported measures. The participants were 13 severe to profoundly hearing impaired people who had previously undergone candidacy assessment for a cochlear implant. Each participant was evaluated on their use and understanding of speech on the telephone. Participants were separated into two groups: those who were candidates for a cochlear implant and those who were not. Speech perception testing was evaluated using a recording of CUNY sentences on the telephone. Results indicated that cochlear implant candidates correctly perceived a significantly lower number of words on the telephone than non-candidates. Use of the telephone was evaluated using a 51-item questionnaire. Results indicated that there was no significant difference in self-reported use of the telephone between cochlear implant candidates and non-candidates. The differences in speech perception understanding on the telephone were most likely due to the overall better hearing levels of the non-candidates. The clinical implications of the present study are considered.