Engineering Commons^™

Direct Current Electrical Stimulation Increases The Fusion Rate Of Spinal Fusion Cages, Jeffrey M. Toth, Howard Seim, Jeffrey D. Schwardt, Wendy B. Humphrey, Joel A. Wallskog, A. Simon Turner

Biomedical Engineering Faculty Research and Publications

Study Design. A randomized experimental evaluation of direct current stimulation in a validated animal model with an experimental control group, using blinded radiographic, biomechanical, histologic, and statistical measures.

Objectives. To evaluate the efficacy of the adjunctive use of direct current stimulation on the fusion rate and speed of healing of titanium interbody fusion cages packed with autograft in a sheep lumbar interbody fusion model.

Summary of Background Data. Titanium lumbar interbody spinal fusion cages have been reported to be 90% effective for single-level lumbar interbody fusion. However, fusion rates are reported to be between 70% and 80% in patients with …

Public Perceptions Of The Midwest’S Pavements - Wisconsin - Phase Iii (Final Report), Marquette University, Department Of Civil, Construction, And Environmental Engineering

Transportation Research Center: Public Perception of Midwest Pavements

The stratified sample furnished by WisDOT and the participants recruited by the WSRL provided a sample adequate for purposes of fulfilling the objectives of Phase III. The sample as furnished by the DOT was skewed towards better pavement quality based on PDI. However, the sample based on IRI was skewed toward poorer quality pavements. The team believes this shows a balanced sample, and the differences in pavement quality between the two indices are the result of the IRI boundaries for the categories. The categories in the two indices should be in closer agreement, although they measure different characteristics.

Overall, the …

Excessive Strand End Slip In Prestressed Piles, Michael F. Petrou, Baolin Wan, Walter S. Joiner, Constantin G. Trezos, Kent A. Harries

Civil and Environmental Engineering Faculty Research and Publications

This paper presents the results of a research project that investigated excessive strand end slip observed recently in some prestressed piles. From measurements taken in the field, it is apparent that the problem o excessive initial strand slip is independent of pile shape and size. Strand end slip is evident in piles of different manufacturers in different states in the Southeast. Excessive strand end slip was found in both the top and bottom of the cross section of the piles, although the top portion of the cross section generally exhibited much higher initial slip. Several preventive measures can be adopted …

Persistence Of Motor Adaptation During Constrained, Multi-Joint, Arm Movements, Robert A. Scheidt, David J. Reinkensmeyer, Michael A. Conditt, W. Zev Reymer, Ferdinando A. Mussa-Ivaldi

Biomedical Engineering Faculty Research and Publications

We studied the stability of changes in motor performance associated with adaptation to a novel dynamic environment during goal-directed movements of the dominant arm. Eleven normal, human subjects made targeted reaching movements in the horizontal plane while holding the handle of a two-joint robotic manipulator. This robot was programmed to generate a novel viscous force field that perturbed the limb perpendicular to the desired direction of movement. Following adaptation to this force field, we sought to determine the relative role of kinematic errors and dynamic criteria in promoting recovery from the adapted state. In particular, we compared kinematic and dynamic …

Influence Of Mortar Rheology On Aggregate Settlement, Michael F. Petrou, Baolin Wan, Francis Gadala-Maria, Venkata Giri Kolli, Kent A. Harries

Civil and Environmental Engineering Faculty Research and Publications

The influence of the rheology of fresh concrete on the settlement of aggregate is examined. Fresh concrete exhibits a yield stress that, under certain conditions, prevents the settlement of coarse aggregate, although its density is larger than that of the suspending mortar. Calculations, based on estimates of the yield stress obtained from slump tests, predict that aggregate normally used in concrete should not sink. To test this prediction, the settlement of a stone in fresh mortar is monitored. The stone does not sink in the undisturbed mortar (which has a high yield stress), but sinks when the mortar is vibrated, …

A New Approach For Computing The Bandwidth Statistics Of Avalanche Photodiodes, Majeed M. Hayat, Guoquan Dong

Electrical and Computer Engineering Faculty Research and Publications

A new approach for characterizing the avalanche-buildup-time-limited bandwidth of avalanche photodiodes (APDs) is introduced which relies on the direct knowledge of the statistics of the random response time. The random response time is the actual duration of the APD’s finite buildup-limited random impulse response function. A theory is developed characterizing the probability distribution function (PDF) of the random response time. Recurrence equations are derived and numerically solved to yield the PDF of the random response time. The PDF is then used to compute the mean and the standard deviation of the bandwidth. The dependence of the mean and the standard …

Main Project Report : Noise And Texture On Pcc Pavements, David Kuemmel, Ronald C. Sonntag, James Crovetti, Yosef Becker, John R. Jaeckel, Allex Satanovsky

Transportation Research Center: Noise & Texture Studies

This report represents the second phase of a project sponsored by the Wisconsin DOT and the FHWA researching the texture and noise characteristics of Portland cement concrete (PCC) pavements. The team of Marquette University and the HNTB Corporation measured noise, texture and friction of 57 test sites in Colorado, Iowa, Michigan, Minnesota, North Dakota and Wisconsin. During 1997, new test sections were constructed in Wisconsin, including random transverse, skewed and longitudinally tined PCC pavements. Interior and exterior noise was measured on all 57 sites using the Fast Fourier Transform method with a Larson-Davis two channel real time acoustical analyzer. Subjective …

Preferences For Permitted And Protected Left-Turn Signal Displays, Alexander Drakopoulos, Richard W. Lyles

Civil and Environmental Engineering Faculty Research and Publications

Twenty-two different signal displays for permitted and protected left turns were evaluated from a driver comprehension perspective. The objective was to identify which alternate signal displays used to convey the same left-turn message to the driver are better comprehended and therefore recommended for use in the field. Protected displays compliant with the Manual on Uniform Traffic Control Devices were found to be better comprehended than certain noncompliant displays; however, some noncompliant permitted displays were found to outperform their compliant counterparts. Regional comprehension biases are nonexistent for the most part, regardless of display compliance with the Manual on Uniform Traffic Control …

Investigative Study Of The Italgrip System - Noise Analysis, David Kuemmel, John Jaeckel, Alex Satanovsky

Transportation Research Center: Noise & Texture Studies

The purpose of this study was to determine if Italgrip is a suitable technique to increase the safety and quality of Wisconsin roadways. The objective of this noise analysis is to identify and quantify any exterior noise impacts of the Italgrip anti-skid surface treatment on PCC pavements. Italgrip is a very thin surface treatment consisting of a two-part polymer resin placed on pavement and covered with re-worked steel slag. Although widely used in Italy, Italgrip has only been available in the United States since 1999.

This study analyzes comparative data from three types of pavement surfaces: untreated transverse tined PCC …

Micro-Ct Image-Derived Metrics Quantify Arterial Wall Distensibility Reduction In A Rat Model Of Pulmonary Hypertension, Roger H. Johnson, Kelly L. Karau, Robert C. Molthen, Steven Thomas Haworth, Christopher A. Dawson

Biomedical Engineering Faculty Research and Publications

We developed methods to quantify arterial structural and mechanical properties in excised rat lungs and applied them to investigate the distensibility decrease accompanying chronic hypoxia-induced pulmonary hypertension. Lungs of control and hypertensive (three weeks 11% O₂) animals were excised and a contrast agent introduced before micro-CT imaging with a special purpose scanner. For each lung, four 3D image data sets were obtained, each at a different intra-arterial contrast agent pressure. Vessel segment diameters and lengths were measured at all levels in the arterial tree hierarchy, and these data used to generate features sensitive to distensibility changes. Results indicate …

On The Assessment Of Stability And Patterning Of Speech Movements, Anne Smith, Michael T. Johnson, Clare Mcgillem, Lisa Goffman

Electrical and Computer Engineering Faculty Research and Publications

Speech requires the control of complex movements of orofacial structures to produce dynamic variations in the vocal tract transfer function. The nature of the underlying motor control processes has traditionally been investigated by employing measures of articulatory movements, including movement amplitude, velocity, and duration, at selected points in time. An alternative approach, first used in the study of limb motion, is to examine the entire movement trajectory over time. A new approach to speech movement trajectory analysis was introduced in earlier work from this laboratory. In this method, trajectories from multiple movement sequences are time- and amplitude-normalized, and the STI …

Scene-Based Nonuniformity Correction With Video Sequences And Registration, Russell C. Hardie, Majeed M. Hayat, Earnest Armstrong, Brian Yasuda

Electrical and Computer Engineering Faculty Research and Publications

We describe a new, to our knowledge, scene-based nonuniformity correction algorithm for array detectors. The algorithm relies on the ability to register a sequence of observed frames in the presence of the fixed-pattern noise caused by pixel-to-pixel nonuniformity. In low-to-moderate levels of nonuniformity, sufficiently accurate registration may be possible with standard scene-based registration techniques. If the registration is accurate, and motion exists between the frames, then groups of independent detectors can be identified that observe the same irradiance (or true scene value). These detector outputs are averaged to generate estimates of the true scene values. With these scene estimates, and …

Public Perceptions Of The Midwest’S Pavements - Introduction, David Kuemmel

Transportation Research Center: Public Perception of Midwest Pavements

The “Public Perceptions of the Midwest’s Pavements” is the largest survey of public perceptions of satisfaction and improvement policies on rural, two-lane highways ever conducted in the 20th Century in the USA. The project was a Pooled Fund effort undertaken by the Wisconsin DOT and included equal participation of the Iowa and Minnesota DOTs. Approximately 4500 drivers and over 1000 highway segments were surveyed in the three states in all three phases of the project, between 1996 and 2000.

The surveys included improvement policy and construction alternative issues and trade-offs, as well as surveys of beliefs and attitudes of the …

Control Strategies For The Transition From Multijoint To Single-Joint Arm Movements Studied Using A Simple Mechanical Constraint, Robert A. Scheidt, W. Zev Rymer

Biomedical Engineering Faculty Research and Publications

Changes were studied in neuromotor control that were evoked by constraining the motion of the elbow joint during planar, supported movements of the dominant arm in eight normal human subjects. Electromyograph (EMG) recordings from shoulder and arm muscles were used to determine whether the normal multijoint muscle activity patterns associated with reaching to a visual target were modified when the movement was reduced to a single-joint task, by pinning the elbow to a particular location in the planar work space. Three blocks of 150 movements each were used in the experiments. Subjects were presented with the unconstrained task in the …

Stochastic Stability Of The Continuous-Time Extended Kalman Filter, K. Reif, S. Gunther, Edwin E. Yaz, R. Unbehauen

Electrical and Computer Engineering Faculty Research and Publications

he error behaviour of the extended Kalman filter is analysed. It is proved that the estimation error remains bounded if the system satisfies a detectability condition and both the initial estimation error and the disturbing noise terms are small enough. Moreover, some selected cases with both bounded and unbounded estimation error are demonstrated by numerical simulations.