Custom Computer Research Articles

Understanding Excessive SNR Loss in Hearing-Impaired Listeners

Traditional audiometric measures, such as pure-tone thresholds or unaided word-recognition in quiet, appear to be of marginal use in predicting speech understanding by hearing-impaired (HI) individuals in background noise with or without amplification. Suprathreshold measures of auditory function (tolerance of noise, temporal and frequency resolution) appear to contribute more to success with amplification and may describe more effectively the distortion component of hearing. However, these measures are not typically measured clinically. When combined with measures of audibility, suprathreshold measures of auditory distortion may provide a much more complete understanding of speech deficits in noise by HI individuals. The primary goal of this study was to investigate the relationship among measures of speech recognition in noise, frequency selectivity, temporal acuity, modulation masking release, and informational masking in adult and elderly patients with sensorineural hearing loss to determine whether peripheral distortion for suprathreshold sounds contributes to the varied outcomes experienced by patients with sensorineural hearing loss listening to speech in noise. A correlational study. Twenty-seven patients with sensorineural hearing loss and four adults with normal hearing were enrolled in the study. The data were collected in a sound attenuated test booth. For speech testing, subjects' verbal responses were scored by the experimenter and entered into a custom computer program. For frequency selectivity and temporal acuity measures, subject responses were recorded via a touch screen. Simple correlation, step-wise multiple linear regression analyses and a repeated analysis of variance were performed. Results showed that the signal-to-noise ratio (SNR) loss could only be partially predicted by a listener's thresholds or audibility measures such as the Speech Intelligibility Index (SII). Correlations between SII and SNR loss were higher using the Hearing-in-Noise Test (HINT) than the Quick Speech-in-Noise test (QSIN) with the SII accounting for 71% of the variance in SNR loss for the HINT but only 49% for the QSIN. However, listener age and the addition of suprathreshold measures improved the prediction of SNR loss using the QSIN, accounting for nearly 71% of the variance. Two standard clinical speech-in-noise tests, QSIN and HINT, were used in this study to obtain a measure of SNR loss. When administered clinically, the QSIN appears to be less redundant with hearing thresholds than the HINT and is a better indicator of a patient's suprathreshold deficit and its impact on understanding speech in noise. Additional factors related to aging, spectral resolution, and, to a lesser extent, temporal resolution improved the ability to predict SNR loss measured with the QSIN. For the HINT, a listener's audibility and age were the only two significant factors. For both QSIN and HINT, roughly 25-30% of the variance in individual differences in SNR loss (i.e., the dB difference in SNR between an individual HI listener and a control group of NH listeners at a specified performance level, usually 50% word or sentence recognition) remained unexplained, suggesting the need for additional measures of suprathreshold acuity (e.g., sensitivity to temporal fine structure) or cognitive function (e.g., memory and attention) to further improve the ability to understand individual variability in SNR loss.

Primary and Revision Total Hip Arthroplasty in Osteogenesis Imperfecta

Due to an increasing lifespan, patients with osteogenesis imperfecta have a high incidence of hip osteoarthritis. The presence of recurrent fractures and deformities make primary and particularly revision total hip arthroplasty challenging. We present a series of patients with osteogenesis imperfecta undergoing total hip arthroplasty at a tertiary referral centre with a median follow-up of 7.6 years (4 to 35 years). There were four primary total hip arthroplasties and eight revision total hip arthroplasties performed in four patients. Three femoral components were custom computer assisted design computer assisted manufactured. The survival rate of the primary total hip arthroplasty was 16% and there were ten complications: five intraoperative fractures, one case of septic loosening and four cases of aseptic loosening. Patients with pre-operative acetabular protrusio were significantly more likely to require revision surgery (p = 0.02). At latest follow-up, the median Oxford hip score was 41 (37 to 46). As the largest series of primary and revision total hip arthroplasty performed in patients with osteogenesis imperfecta, we report good medium to long-term outcomes. Preoperative planning and consideration of custom made prostheses have an important role in these complex cases.

Are computers good or bad for business? How mediated customer–computer interaction alters emotions, impressions, and patronage toward organizations

Are computers good or bad for business? Although computers are social actors research finds that people react to computers and humans with similar tendencies, little research directly compares human–computer interaction to human–human interaction. I ask how mediated transactions with a company’s human or computer representatives alter customers’ reactions toward that company. I conduct an experiment where subjects in the role of customers received products (low or high quality) from a representative (human or computer). I measure the customer’s emotions, impressions, and patronage toward both the representative and the organization. The data indicate few differences in reactions toward the representative and the organization, however, customers perceive the organization as more responsible and in control when they have employed human, not computer, representatives. A hypothesized statistical interaction effect (a moderation effect) on several emotions indicates that computer representatives decrease the strength of the relationship between receiving low or high quality products and customer’s emotions. Although many customer reactions indicate no human/computer differences, I discuss how the statistical moderation effect of computer identity on several emotions may relate to computers are social actors and other research.

Abstract 332: STI Assessment of Left Ventricular Function in Patients With Previous Myocardial Infarction and Recurrent Ventricular Arrhythmias

Purpose. Our aim was to compare strain parameters of patients with structural heart disease with and without ventricular tachycardia (VT) in order to identify high-risk patients that could have been missed by left ventricular ejection fraction (LVEF) criteria. Methods. We studied 86 patients (pts) with previous myocardial infarction (age, 59±14 years) scheduled for cardioverter-defibrillator (ICD) implantation. Forty-three pts had documented VT and 43 pts presented with no VT. Left ventricular (LV) function and volumes and score index were determined by two-dimensional echocardiography. Longitudinal LV strain was defined as the average of negative longitudinal strains of 6 segments of the septal and lateral walls in the apical 4-chamber view. Average radial and circumferential strain of 6 mid-LV segments was determined in the mid-short-axis view. Global strain was obtained by averaging the maximum systolic shortening in a 16-segment model. The analysis of strain parameters was performed offline using customized computer software (EchoPAC BT09, GE Ultrasound). Results. There were no differences in LVEF, LV volumes, QRS and QTc duration between pts with or without VT occurring during follow-up. Multivariate analysis revealed that global (p=0.018) and posterior wall circumferential strain (p=0.007) were strong and independent predictors of the occurrence of arrhythmic events. The area under the curve (AUC) for posterior wall circumferential strain was 0.79 and the optimal cutoff value -6.2% for a sensitivity of 71% and a specificity of 89% in predicting arrhythmic events. AUC for QTc was 0.32 yielding a sensitivity and specificity of, respectively, 49% and 65% to predict arrhythmias and AUC for EF was 0.51 yielding a sensitivity and specificity of, respectively, 56% and 70%. Conclusions. Circumferential strain was the strongest predictor of spontaneous ventricular arrhythmias among other clinical and echocardiographic variables such as score index and LV function and volumes in patients with previous myocardial infarction scheduled for ICD therapy.

Data for Free—Can an Electronic Medical Record Provide Outcome Data for Incontinence/Prolapse Repair Procedures?

We determined whether a custom computer program can improve the extraction and accuracy of key outcome measures from progress notes in an electronic medical record compared to a traditional data recording system for incontinence and prolapse repair procedures. Following institutional review board approval, progress notes were exported from the Epic electronic medical record system for outcome measure extraction by a custom computer program. The extracted data (D1) were compared against a manually maintained outcome measures database (D2). This work took place in 2 phases. During the first phase, volatile data such as questionnaires and standardized physical examination findings using the POP-Q (pelvic organ prolapse quantification) system were extracted from existing progress notes. The second phase used a progress note template incorporating key outcome measures to evaluate improvement in data accuracy and extraction rates. Phase 1 compared 6,625 individual outcome measures from 316 patients in D2 to 3,534 outcome measures extracted from progress notes in D1, resulting in an extraction rate of 53.3%. A subset of 3,763 outcome measures from D1 was created by excluding data that did not exist in the extraction, yielding an accuracy rate of 93.9%. With the use of the template in phase 2, the extraction rate improved to 91.9% (273 of 297) and the accuracy rate improved to 100% (273 of 273). In the field of incontinence and prolapse, the disciplined use of an electronic medical record template containing a preestablished set of key outcome measures can provide the ideal interface between required documentation and clinical research.

The challenge of designing for diversity in older users

Purpose: The older population is not a homogenous group and show significant diversity in constitution, capabilities and experience. In order for new and emerging digital technologies to be inclusive, it is crucial to encompass this diversity and employ a design process that is sensitive to it. Current approaches to inclusive design tend to seek one design for all, focusing on users who are least engaged with digital technology. In this paper we outline an alternative approach to inclusive design based on co-design with both digitally engaged and unengaged user groups. In our study, as part of a multi-disciplinary group in the New Dynamics of Ageing (UK) funded collaborative research project, older people from different walks of life were invited to four different themed workshops called ‘sandpits’ to explore current and emerging technologies in a playful and creative context to help them envisage the potential implications these technologies can have in their lives as well as to identify key issues and user requirements for further development. This paper will discuss the outcome from three of those sandpits. The themes explored in these three sandpits were 1) Custom computers for older people 2) Supporting Identity and memory in later life and 3) Social connections with new technology. Methods. A total of 66 older people participated in the three sandpits conducted between 2009 and 2010. Separated into PC and non-PC users groups, they were involved in discussions and shown open ambiguous envisionments that responded to the themes through hands-on demonstration, role-play or dramatic enactment of their use. Broadly taking into account the role of technology generations effects, the envisionments were modeled and presented as appliances, incorporating forms of products and interactions that older people are familiar with to encourage in-clusion. The older participants were then involved in the redesign of these envisionments through a collaborative design process. Results and discussion The design responses from older PC and non-PC user groups revealed a difference in the type of embodiment they want for Internet-enabled applications. Both groups redesigned the concepts based on their experience, interests, familiarity with the technology they have and its associated infrastructure or lack thereof. In general, non-PC user groups preferred the appliance nature of the envisionments, and incorporated the functions they were interested in performing, such as capturing spoken stories, sharing photographs, chatting over TV programmes, etc into these appliances. In contrast, PC owners questioned the need for separate appliances and often re-designed them as PC applications or Internet services with emphasis placed on modality and compatibility with their existing infrastructure. The paper will discuss the difficulty and challenge of bridging the gap between the diversity of technology and its users.

Implementation of linear model predictive control using a field-programmable gate array

This study investigates the design of a field-programmable gate array-based custom computer architecture solution for implementing model predictive control (MPC). The solution employs a primal logarithmic-barrier interior-point algorithm in order to handle actuator constraints. The solution also incorporates practical aspects of a control algorithm including state observation and data sampling. The resulting circuit is profiled by application to a disturbance rejection control problem of a 14th-order lightly damped flexible beam structure with actuator constraints. This is achieved at 2 kHz sampling frequency and with 16-sample prediction horizon.

Design and simulation of an SMS driven microcontroller for home automation using proteus software

Technology has moved from a level at which a user is always present in a place before he/she can control or do anything at the place. Imagine what television used to be before the inception of remote control. With the inception of remote control, the television can be controlled while lying on the bed or sitting down on the chair. You do not have to move towards it and press the button on it before you can control it. Now envision how it will be, being able to control your entire home appliances automatically and even remotely. Different types of technology are available to do this but this paper looks at designing and simulating the usage of an SMS from mobile phone together with microcontroller (PIC16F876) in communicating with and controlling home appliances. The firmware is written in C language and translated into a Hexadecimal file using Custom Computer Services (CCS) Compiler. The translated Hexadecimal file is loaded into the microcontroller and the microcontroller is then interfaced with the mobile phone such that when this phone receives SMS, it gives the detail of the state of the home appliances remotely. SMS can be sent to instruct the system to do some specific tasks like switching on or off of any of the appliances in the home, switching on the pumping machine to pump water and monitor it. Anytime one feels like stopping an invoked action, it can be done remotely without being in the vicinity of the equipment. Key words: Home automation, short message service, custom computer services compiler, simulation, microcontroller, general packet radio system networks, proteus software, firmware.

High-Fidelity, Low-Cost, Automated Method to Assess Laparoscopic Skills Objectively

We sought to define the extent to which a motion analysis-based assessment system constructed with simple equipment could measure technical skill objectively and quantitatively. An "off-the-shelf" digital video system was used to capture the hand and instrument movement of surgical trainees (beginner level = PGY-1, intermediate level = PGY-3, and advanced level = PGY-5/fellows) while they performed a peg transfer exercise. The video data were passed through a custom computer vision algorithm that analyzed incoming pixels to measure movement smoothness objectively. The beginner-level group had the poorest performance, whereas those in the advanced group generated the highest scores. Intermediate-level trainees scored significantly (p < 0.04) better than beginner trainees. Advanced-level trainees scored significantly better than intermediate-level trainees and beginner-level trainees (p < 0.04 and p < 0.03, respectively). A computer vision-based analysis of surgical movements provides an objective basis for technical expertise-level analysis with construct validity. The technology to capture the data is simple, low cost, and readily available, and it obviates the need for expert human assessment in this setting.

Patellofemoral arthroplasty, where are we today?

Patellofemoral arthroplasty remains controversial, primarily due to the high failure rates reported with early implants. Numerous case series have been published over the years detailing results of various first- and second-generation implants. The purpose of this work is to summarize results published to date and identify common themes regarding implants, surgical techniques, and indications in order to maximize results of future procedures. A comprehensive review of the MEDLINE database was carried out to identify all clinical studies related to patellofemoral arthroplasty. First-generation resurfacing implants were associated with relatively high failure rates in the medium term. Second-generation implants, with femoral cuts based on TKA designs have yielded more promising medium-term results. Surgical indications are specific and must be carefully followed to minimize poor results. Short-term complications are generally related to patellar maltracking, while long-term complications are generally related to progression of osteoarthritis in the tibiofemoral joint. Implant loosening and polyethylene wear are rarely reported. Short-term results are favourable for new technology including custom implants and computer navigated surgery. Overall, recent improvements in implant design and surgical techniques have resulted in improvements in short- and medium-term results. More work is required to assess the long-term outcomes of modern implant designs. IV.

Effects of viscosity on sperm motility studied with optical tweezers

The purpose of this study is to analyze human sperm motility and energetics in media with different viscosities. Multiple experiments were performed to collect motility parameters using customized computer tracking software that measures the curvilinear velocity (VCL) and the minimum laser power (Pesc) necessary to hold an individual sperm in an optical trap. The Pesc was measured by using a 1064 nm Nd:YVO(4) continuous wave laser that optically traps motile sperm at a power of 450 mW in the focused trap spot. The VCL was measured frame by frame before trapping. In order to study sperm energetics under different viscous conditions sperm were labeled with the fluorescent dye DiOC(6)(3) to measure membrane potentials of mitochondria in the sperm midpiece. Fluorescence intensity was measured before and during trapping. The results demonstrate a decrease in VCL but an increase in Pesc with increasing viscosity. Fluorescent intensity is the same regardless of the viscosity level indicating no change in sperm energetics. The results suggest that, under the conditions tested, viscosity physically affects the mechanical properties of sperm motility rather than the chemical pathways associated with energetics.

Domain-specific programmable design of scalable streaming-array for power-efficient stencil computation

This paper presents the domain-specific programmable design of custom computing machines for high-performance stencil computation. Stencil computation is one of the typical kernels in scientific computations, however its low operational-intensity makes the sustained performance limited by memory bandwidth on recent microprocessors and GPUs. So far we have proposed a scalable streaming-array (SSA) of processing elements, which provides almost linear scalability by increasing FPGAs with a constant externalmemory bandwidth. In order to facilitate custom computing and efficiently utilize hardware resources for various and complex stencil-computations, we design programmable SSA with limited but necessary functionality. We show the design concept, the programmable structure and the SIMD instruction set for SSA. Prototype implementation with nine FPGAs demonstrates that our programmable design with a lot of floating-point units exploits hardware resources well, efficiently achieving 260 GFlop/s, which is 87.4% of the peak, at 1295 MFlop/sW.

Prediction of orthodontic treatment of surgically exposed unilateral maxillary impacted canine patients

To determine whether clinical variables associated with surgically exposed unilateral maxillary impacted canine cases are predictors for orthodontic treatment choices involving (1) extraction, (2) expansion, (3) extraction and expansion, or (4) nonextraction and nonexpansion. A retrospective study of records of 97 cases meeting the inclusion criteria with unilateral maxillary impacted canines from three private practices were reviewed for gender, age, molar classification, impaction location and angulation, and presence of pretreatment maxillary and mandibular casts and cephalograms. Maxillary and mandibular transverse dimensions and lower incisor crowding were obtained from occlusal cast images using custom computer software. Skeletal analysis and incisor angulation and position were obtained from digitized cephalometric tracings. Statistical comparisons were made to determine parameters orthodontists could use to develop an orthodontic treatment plan. Subjects with Class II end-on molars on the nonaffected side were less likely to have extraction and/or expansion. Subjects with extraction and/or expansion had decreased lower incisor to mandibular plane, available canine space, maxillary premolars, and molar transverse dimensions and an increased mandibular incisor Irregularity Index compared with nonextraction/nonexpansion subjects. Using a multiple-variable model, available canine space was the single most important predictor of extraction and/or expansion, followed by maxillary molar transverse dimension and mandibular incisor Irregularity Index. Available canine space, maxillary transverse dimension at the molars, and the mandibular incisor Irregularity Index serve as indicators for extraction and/or expansion in cases involving unilateral maxillary impacted canines requiring surgical exposure. Many of these cases are treated without extraction and/or expansion.

Digital Subtraction Phonocardiography (DSP) applied to the detection and characterization of heart murmurs

BackgroundDuring the cardiac cycle, the heart normally produces repeatable physiological sounds. However, under pathologic conditions, such as with heart valve stenosis or a ventricular septal defect, blood flow turbulence leads to the production of additional sounds, called murmurs. Murmurs are random in nature, while the underlying heart sounds are not (being deterministic).InnovationWe show that a new analytical technique, which we call Digital Subtraction Phonocardiography (DSP), can be used to separate the random murmur component of the phonocardiogram from the underlying deterministic heart sounds.MethodsWe digitally recorded the phonocardiogram from the anterior chest wall in 60 infants and adults using a high-speed USB interface and the program Gold Wave http://www.goldwave.com. The recordings included individuals with cardiac structural disease as well as recordings from normal individuals and from individuals with innocent heart murmurs. Digital Subtraction Analysis of the signal was performed using a custom computer program called Murmurgram. In essence, this program subtracts the recorded sound from two adjacent cardiac cycles to produce a difference signal, herein called a "murmurgram". Other software used included Spectrogram (Version 16), GoldWave (Version 5.55) as well as custom MATLAB code.ResultsOur preliminary data is presented as a series of eight cases. These cases show how advanced signal processing techniques can be used to separate heart sounds from murmurs. Note that these results are preliminary in that normal ranges for obtained test results have not yet been established.ConclusionsCardiac murmurs can be separated from underlying deterministic heart sounds using DSP. DSP has the potential to become a reliable and economical new diagnostic approach to screening for structural heart disease. However, DSP must be further evaluated in a large series of patients with well-characterized pathology to determine its clinical potential.

Concentrating sunlight with an immobile primary mirror and immobile receiver: Ray-tracing results

Abstract Using a combination of custom computer code and commercially available ray-tracing software, we explore variations of concentrator geometries where sunlight is first incident onto a stationary primary mirror of circular cross section. The reflected radiation is incident onto a smaller, secondary moveable mirror, which focuses the radiation onto a stationary target. Simulations for this trough geometry show peak concentrations of 38 solar equivalents.

Use of custom surgical stents for facial bone contouring - a new technique

Custom computer software and computer-generated surgical drill guides are widely used in the planning and placement of osseointegrated dental implants. Manipulation and interaction with facial CT data in three dimensions (3D) permits the experienced operator to predictably place implants into predetermined sites both intra- and extra-orally. Similar technology allows manipulation of the 3D data in cases of pathological bony deformity in order to determine a surgical plan. However, whilst on screen planning may be straightforward, translating the ‘virtual’ plan into reality is far from straightforward.

Discriminant Analysis of Native Thoracic Aortic Curvature: Risk Prediction for Endoleak Formation After Thoracic Endovascular Aortic Repair

Purpose To determine the association of native thoracic aortic curvature measured from computed tomographic (CT) angiography categorized by discriminant analysis with the development of endoleaks after thoracic endovascular aortic repair (EVAR). Materials and Methods Forty patients (28 men, 12 women; mean age, 74 y; range, 40–89 y) with aortic diseases treated with thoracic EVAR were evaluated. Diseases treated included atherosclerotic aneurysm (n = 27), penetrating atherosclerotic ulcer (n = 4), intramural hematoma (n = 3), mycotic aneurysm (n = 3), and anastomotic pseudoaneurysm (n = 3). Quantitative analysis of native aortic morphology was performed on preprocedural CT angiograms with an original customized computer program, and regional curvature indices in each anatomic segment of the aorta were calculated. Patterns of native thoracic aortic morphology were analyzed by discriminant analysis. The association between the morphologic pattern of the aorta and the presence and type of endoleak was assessed. Results After leave-one-out cross-validation methods had been applied, the sensitivity, specificity, and accuracy to detect endoleak formation in a new population group by discriminant analysis of the patterns of native aortic curvature were estimated as 84.0%, 58.8%, and 73.8%, respectively. Compared with the no-endoleak group, the type Ia endoleak group had greater curvature at the aortic arch, the type Ib endoleak group had greater curvature at the thoracoabdominal junction, and the type III endoleak group had greater curvature in the midportion of the descending aorta. Conclusions Discriminant analysis of native thoracic aortic morphology measured from CT angiography is a useful tool to predict the risk of endoleak formation after thoracic EVAR and should be implemented during treatment planning and follow-up.

Internal Force Analyzing of Plane Frame Structure Based on Interaction Theory

Based on researchers of interaction theory and its application, mechanism of interaction among superstructure, base and foundation was analyzed and a design method was proposed. Combining with engineering construction cases, change law of internal force of superstructure in interaction system was researched through comparing results between interaction analyzing method and custom computation method. Some meaningful engineering design devices were concluded finally.

Convex Lens-Induced Confinement for Imaging Single Molecules

Fluorescence imaging is used to study the dynamics of a wide range of single molecules in solution or attached to a surface. Two key challenges in this pursuit are to image immobilized single molecules in the presence of a high level of fluorescent background, and to image freely diffusing single molecules for long times. We present a simple modification to a wide-field fluorescence microscope that addresses both challenges and dramatically improves single-molecule imaging. The Convex Lens Induced Confinement (CLIC) system restricts molecules to a wedge-shaped gap of nanoscale depth. The shallow depth of the imaging volume leads to up to 20-fold greater rejection of background fluorescence than is achieved with total internal reflection fluorescence (TIRF) imaging. The elimination of out-of-plane diffusion leads to approximately 10,000-fold longer diffusion-limited observation time per molecule than is achieved with confocal detection in free solution. The restriction of freely diffusing molecules to gaps whose depth is greater than the molecular diameter provides a simple measure of molecular size. The CLIC system may be implemented using a minor modification to a standard flow cell, and does not require any nanofabrication, nor any custom optics, electronics, or computer control. We demonstrate the advantageous properties of CLIC measurements by imaging singly labeled surface-immobilized DNA molecules in the presence of a high concentration of free dye (up to 2 micromolar); by counting the transmembrane proteins in freely diffusing lipid vesicles; and by measuring the sizes of freely diffusing proteins and DNA with diameters ranging from 3nm to 200 nm. Further, we apply CLIC to probe weak intermolecular interactions in a range of systems.

Missing not at random models for latent growth curve analyses.

The past decade has seen a noticeable shift in missing data handling techniques that assume a missing at random (MAR) mechanism, where the propensity for missing data on an outcome is related to other analysis variables. Although MAR is often reasonable, there are situations where this assumption is unlikely to hold, leading to biased parameter estimates. One such example is a longitudinal study of substance use where participants with the highest frequency of use also have the highest likelihood of attrition, even after controlling for other correlates of missingness. There is a large body of literature on missing not at random (MNAR) analysis models for longitudinal data, particularly in the field of biostatistics. Because these methods allow for a relationship between the outcome variable and the propensity for missing data, they require a weaker assumption about the missing data mechanism. This article describes 2 classic MNAR modeling approaches for longitudinal data: the selection model and the pattern mixture model. To date, these models have been slow to migrate to the social sciences, in part because they required complicated custom computer programs. These models are now quite easy to estimate in popular structural equation modeling programs, particularly Mplus. The purpose of this article is to describe these MNAR modeling frameworks and to illustrate their application on a real data set. Despite their potential advantages, MNAR-based analyses are not without problems and also rely on untestable assumptions. This article offers practical advice for implementing and choosing among different longitudinal models.