Biomedical subjects

Steven F Barrett

Publications and source records attributed to Steven F Barrett.

16 recordsLinked to original sources

PubMed2005

University of Wyoming College of Engineering undergraduate design projects to aid Wyoming persons with disabilities, a mid-program review.

In Spring 2002 the University of Wyoming received National Science Foundation funding from the Division of Bioengineering and Environmental Systems to provide a meaningful design experience for University of Wyoming, College of Engineering students that will directly aid individuals with disabilities within the state of Wyoming. At the 2003 RMBS we presented a paper on the value of starting such a program. We have found that students receive a much richer capstone design experience when developing a project for direct use by a challenged individual. We are now approximately midway through this project. Since its inception the program has blossomed to include serving individuals in several regional states, outreach short courses to the community, projects have become of increasing difficulty and involve interdisciplinary teamwork, and many challenged individuals have been provided specialized one of a kind assistive devices. In this paper we will report on these advancements, lessons learned, and benefits received by participating in this vital program.

Biomedical Engineering↗

PubMed2005

Biomimetic machine vision system.

Real-time application of digital imaging for use in machine vision systems has proven to be prohibitive when used within control systems that employ low-power single processors without compromising the scope of vision or resolution of captured images. Development of a real-time machine analog vision system is the focus of research taking place at the University of Wyoming. This new vision system is based upon the biological vision system of the common house fly. Development of a single sensor is accomplished, representing a single facet of the fly's eye. This new sensor is then incorporated into an array of sensors capable of detecting objects and tracking motion in 2-D space. This system "preprocesses" incoming image data resulting in minimal data processing to determine the location of a target object. Due to the nature of the sensors in the array, hyperacuity is achieved thereby eliminating resolutions issues found in digital vision systems. In this paper, we will discuss the biological traits of the fly eye and the specific traits that led to the development of this machine vision system. We will also discuss the process of developing an analog based sensor that mimics the characteristics of interest in the biological vision system. This paper will conclude with a discussion of how an array of these sensors can be applied toward solving real-world machine vision issues.

Algorithms↗

PubMed2005

The segmentation and visualization of a neuron in the housefly's visual system.

Those studying biological systems are often interested in the morphology of the various microscopic organelles. The three dimensional reconstruction and visualization of objects provide a powerful tool to understand the nature of each object, and its relationship to other objects. Segmentation is the key to 3D analysis and study of objects that have been recorded with a series of sectioned images, such as from a confocal laser scanning microscope (CLSM). Segmentation is the process of completely separating or isolating the individual objects in an image. A seed-based semi-automatic segmentation tool has been developed to aid in the process of 3D visualization of objects recorded with serial sectioned images, including a boundary creation method that maintains the separate identity of contacting objects. This segmentation tool also allows the user to retain background information as a separate object, providing important reference and landmark information for the object of interest. This paper summarizes the main parts of the segmentation algorithm and presents 3D reconstructions of visual neurons of the housefly, Musca domestica. These reconstructions are compared to typical 3D images produced from other widely used software packages, including standard CLSM imaging software and the popular ImageJ supported by National Institute of Health (NIH). Efforts are underway to develop a user-friendly graphical user interface (GUI) for the segmentation algorithm to entice broader used in research settings.

Algorithms↗

PubMed2005

Using parallel evolutionary development for a biologically-inspired computer vision system for mobile robots.

We describe a new approach to attacking the problem of robust computer vision for mobile robots. The overall strategy is to mimic the biological evolution of animal vision systems. Our basic imaging sensor is based upon the eye of the common house fly, Musca domestica. The computational algorithms are a mix of traditional image processing, subspace techniques, and multilayer neural networks.

Algorithms↗

PubMed2005

Two assistive technology devices for children: an adjustable reacher and a lunch room chair.

Two devices were modified and redesigned to further improve on previous designs and to better suit the children they were originally constructed for. The first device is a reacher that needs to be adjustable. The child originally needed a reacher that was small enough to operate. Adult reachers were shortened to fit the child. It became apparent that the reachers would need to be able to grow with the child. For that reason a reacher was developed with interchangeable center sections and control rods. This allows the reacher to grow with child in increments without the need to keep sending the reacher in for modification. The reacher also needs to pinch on a different plane then it is controlled at to simplify use for the child. The second device modified was a chair built for children in wheel chairs to allow for them to sit with their peers at a lunch table at school. The chair was totally redesigned to be more comfortable and stronger. A removable cover was added so that it can be washed. A leg rest with adjustable foot rests was added so the children's feet are well supported and they are comfortable. This chair will allow the children to sit anywhere in the cafeteria so that they may sit with their peers.

Activities of Daily Living↗

PubMed2005

Safety enhancement of a specialized power assisted tricycle for a child with osteogenesis imperfecta type III.

A child in the community of Laramie, Wyoming was born with Osteogenesis Imperfecta which is a genetic disorder that limits the physical abilities, size, and strength of the child. A customized power assisted tricycle was developed, which offered a unique opportunity to serve multiple purposes in his childhood development. This tricycle will ultimately provide him with the opportunity to gain muscle mass, strength, coordination, and confidence. The tricycle was completed as a senior design project in 2002, funded by the National Science Foundation, Biomedical Engineering Program and research to Aid Persons with Disabilities Program and University of Wyoming, College of Engineering Undergraduate Design Project to Aid Wyoming Persons with Disabilities. Unfortunately, the tricycle did not provide the necessary features to allow him to ride the tricycle safely. For this reason the tricycle was redesigned to include many different redundant safety systems which allows the tricycle to be safe for the child's use. Being funded by the same grant, new systems were added to the tricycle. A panic kill switch, automatic brakes, numerous redundant velocity sensors, tip over prevention circuitry, a redesigned operating system, a battery recharge port, and other systems were added, allowing for the tricycle to provide a high level of safety. A great deal of testing and sound design practices have been taken into consideration throughout the addition of these systems. Without these improvements, the child would not have the opportunity to use the tricycle to help with his development.

Bicycling↗

PubMed2004

An improved Morris Water Maze tracking algorithm for psychophysical studies.

An algorithm to track a rat swimming in a Morris Water Maze has been developed. The system is automatically configured to any pool and relative suitable light conditions. It tracks the rat's position and head pose 10 times per second. The output data is displayed in a bitmap and also in a text file. The system was tested with an X - Y plotter using a simulated rat swimming in the maze. Known signals were provided to a model rat and compared to the position and pose information provided by the tracking algorithm. The algorithm was able to track rat velocities up to 2.32 m/s, localize rat position to 4 mm within the maze, and provide head pose information. Early prototypes of the algorithm were also used to track actual rats in a water maze.

Algorithms↗

PubMed2004

Edge encoding mechanisms in Musca domestica.

Musca domestica, the common house fly, has a simple yet powerful and accessible vision system. Cajal indicated in 1885 the vision system is the same as in the human retina [1]. We have modeled the intracellular connections of the vision system and have applied high resolution images to the model. Even though the animal does not have what we would consider a high resolution imaging system, it is still capable of high resolution and we are using the same processing principles to extract high resolution information from the visual input. In this paper we will discuss how we are using a purely local process from a single cartridge within the vision system to encode edge information: magnitude, orientation, displacement, and tilt. We also investigate a cooperative approach to link cartridges that have common numerical features in their field of view to share their information for potential edge connection and feature extraction.

Animals↗

PubMed2004

University of Wyoming, College of Engineering, Undergraduate Senior Design Project: the talking hand.

A glove was built using flex sensors to produce a voltage according to the amount of bend each finger produces when signing a letter of the alphabet. The glove detects and outputs in text the letter of the alphabet being signed as the wearer signs the different letters. The amount of bend causes a change in resistance, which in turn produces a specific voltage in accordance to the letter being signed. That voltage is then fed into a data acquisition card that runs into a personal computer. Through intensive programming and training of a special algorithm called a neural network; the input voltage to the data acquisition card will result in that letter being displayed in font on the monitor of the computer. The computer is then programmed to take the text that is displayed on the monitor and run it out of the PC into a store bought chipset that will convert the text to speech. Therefore, a person will be able to put on this glove, sign all twenty-six letters of the alphabet, see the letter they are currently signing output on the monitor, and hear it spoken in a pre-recorded voice.

Algorithms↗

PubMed2003

Edge encoding mechanisms in the parallel L4 neuron array of the fly (Musca domestica).

The current model of fly's cartridge termed Olson's Algorithm employs seven photoreceptors (R1-R6, Rref) to encode edge orientation. The models provide a sinusoidal output for an edge rotated about the reference photoreceptor. Although the model is powerful in providing insight into a fly's visual apparatus, it has several shortcomings. The model: does not respond to horizontal edges, does not provide Gaussian overlapped weighting of the photoreceptors which provides hyperacuity capability, and does not provide for a unique encoding of edge information. We are currently working on modifications to the model to remedy these issues. These issues must be resolved prior to pursuing object segmentation, tracking, and identification. In this paper we will investigate enhancements to the model and what they provide in solving some of the issues.

Algorithms↗

PubMed2003

Segmentation and 3D reconstruction of biological cells from serial slice images.

Our understanding of the world around us and the many objects that we encounter is based primarily on three-dimensional information. It is simply part of the environment in which we live and the intuitive nature of our interpretation of our surroundings. In the arena of biomedical imaging, the image information most often collected is in the form of two-dimensional images. In cases where serial slice information is obtained, such as MRI images, it is still difficult for the observer to mentally build and understand the three-dimensional structure of the object. Although most image rendering software packages allow for 3D views of the serial sections, they lack the ability to segment, or isolated different objects in the data set. Typically the task of segmentation is performed by knowledgeable persons who tediously outline or label the object of interest in each image slice containing the object [1,2]. It remains a difficult challenge to train a computer to understand an image and aid in this process of segmentation. This article reports of on-going work in developing a semi-automated segmentation technique. The approach uses a Leica Confocal Laser Scanning Microscope (CLSM) to collect serial slice images, image rendering and manipulating software called IMOD (Boulder Colorado), and Matlab (The Mathworks Inc.) image processing tools for development of the object segmentation routines. The initial objects are simple fluorescent microspheres (Molecular Probes), which are easily imaged and segmented. The second objects are rat enteric neurons, which provide medium complexity in shape and size. Finally, the work will be applied to the biological cells of the household .y, Musca domestica, to further understand how its vision system operates.

Algorithms↗

PubMed2003

Life's a switch. Experiences in NSF undergraduate design projects.

During the summer of 2002 Stephanie Popp and Jennifer Barnes developed a manual, "Life's a Switch," through a project funded by the National Science Foundation. This manual teaches people how to build their own cost effective assistive switches. Assistive switches are a form of assistive technology which includes any device that enhances a person's quality of life by improving the individual's mobility, ability to perform daily activities, enhancing communication, or allowing participation in education, vocational activities and recreation. One main goal of assistive technology is to provide opportunities for children with disabilities to explore, play, learn, and communicate with others. Switches are essential tools used to provide these opportunities. When a child with developmental disabilities understands the connection between the activation of a switch and the resulting action it triggers, the knowledge of cause and effect is gained. Therefore, the basis for all future learning is established [1]. One of the current problems facing assistive switch users is the cost of available items. This project provides more affordable solutions for switch users by teaching the families and educators of switch users how to make their own switches and adaptors in the "Life's a Switch" manual. For example, some assistive technology vendors sell large button switches from $25.00 to $45.00, tread switches for $40.00, and pillow switches for $35.00 [2]. Amazingly, all parts and tools used to make these assistive switches can be bought and made into personally designed assistive devices averaging a cost of around $10.00 [3]. A workshop to teach this manual was also developed. This workshop will spread awareness of the more affordable options this project sets forth. In September of 2002, the first workshop was held in a laboratory classroom at the University of Wyoming's College of Engineering. Each attendant was provided with a kit that included all essential tools and components needed to make an assistive switch. Workshops scheduled into 2003 will provide educational opportunities for participants as well as opportunities for improvement of the manual.

Biomedical Engineering↗

PubMed2003

University of Wyoming, College of Engineering, undergraduate design project: star tracer.

The University of Wyoming received funding in the spring of 2002 from the National Science Foundation Division of Bioengineering and Environmental Systems in order to complete undergraduate design projects. One design project that was chosen by the College of Engineering involved partnering with the College of Education. The College of Education's Special Education Department needed some visual teaching aids to be redesigned and then built. Two undergraduate students were hired throughout the summer of 2002 under NSF REU funding in order to develop thirty new teaching devices. These devices were going to be used to educate middle school students about the effects of possessing a learning disability. The teaching aids are specifically designed for simulating the affects of dyslexia. The new teaching aids required improved transportability and durability, quicker setup time, and a lighter weight. Throughout the summer, the teaching aids were redesigned and built by an undergraduate student team from the College of Engineering, and have since provided many benefits for the state of Wyoming.

Biomedical Engineering↗

PubMed2003

University of Wyoming, College of Engineering, undergraduate design projects to aid Wyoming persons with disabilities.

In Spring 2002 the University of Wyoming received NSF funding from the Division of Bioengineering and Environmental Systems to provide a meaningful design experience for University of Wyoming, College of Engineering students that will directly aid individuals with disabilities within the state of Wyoming. Other universities have participated in this very worthwhile program [1, 2, 3]. To achieve the program purpose, the following objectives were established: Provide engineering students multi-disciplinary, meaningful, community service design projects, Provide persons with disabilities assistive devices to empower them to achieve the maximum individual growth and development and afford them the opportunity to participate in all aspects of life as they choose, Provide engineering students education and awareness on the special needs and challenges of persons with disabilities, and Provide undergraduate engineering students exposure to the biomedical field of engineering. To accomplish these objectives the College of Engineering partnered with three organizations that provide education and service related to disability. Specifically, the college has joined with the Wyoming Institute for Disabilities (WIND) assistive technology program, Wyoming New Options in Technology (WYNOT) and their Sports and Outdoor Assistive Recreation (SOAR) project along with the university's Special Education program. In this paper we will describe how the program was created, developed, and its current status.

Biomedical Engineering↗

PubMed2002

Biologically based machine vision: signal analysis of monopolar cells in the visual system of Musca domestica.

Machine vision for navigational purposes is a rapidly growing field. Many abilities such as object recognition and target tracking rely on vision. Autonomous vehicles must be able to navigate in dynamic enviroments and simultaneously locate a target position. Traditional machine vision often fails to react in real time because of large computational requirements whereas the fly achieves complex orientation and navigation with a relatively small and simple brain. Understanding how the fly extracts visual information and how neurons encode and process information could lead us to a new approach for machine vision applications. Photoreceptors in the Musca domestica eye that share the same spatial information converge into a structure called the cartridge. The cartridge consists of the photoreceptor axon terminals and monopolar cells L1, L2, and L4. It is thought that L1 and L2 cells encode edge related information relative to a single cartridge. These cells are thought to be equivalent to vertebrate bipolar cells, producing contrast enhancement and reduction of information sent to L4. Monopolar cell L4 is thought to perform image segmentation on the information input from L1 and L2 and also enhance edge detection. A mesh of interconnected L4's would correlate the output from L1 and L2 cells of adjacent cartridges and provide a parallel network for segmenting an object's edges. The focus of this research is to excite photoreceptors of the common housefly, Musca domestica, with different visual patterns. The electrical response of monopolar cells L1, L2, and L4 will be recorded using intracellular recording techniques. Signal analysis will determine the neurocircuitry to detect and segment images.

Animals↗

PubMed2002

Image processing and 3D reconstruction of serial section micrographs from Musca Domestica's biological cells responsible for visual processing.

The ability to visualize and understand three-dimensional objects from two-dimensional cross-section or slice images is difficult, even if the observer has a general concept of the object of interest. The focus of this research is to apply image-processing methods to two-dimensional cross-section electron transmission micrographs of the biological cells of the Musca Domestica's, or household fly's visual system in an effort to better understand the cells responsible for processing visual information. The application of knowledge gained from biological systems is know as biomimetics. The first task will be to construct a useful three-dimensional data set from two-dimensional micrographs provided by the U.S. Air Force Academy in Colorado Springs, Colorado. The data set will be constructed by aligning these images in an edge-to-edge fashion to form a layer. Once each layer is reconstructed, the layers will be stacked and registered to form the third dimension of the data set. This task is complicated by the fact that translation, rotation and scaling mismatches exist in the images. The second task will be to segment and label the biological cells of interest. Computerized segmentation has not yet proved successful, resulting in a manual or "brain-powered" approaches being used at many institutions. By using and modifying current computer image-processing techniques, advances leading to a semi-automated segmentation process may result. Finally, the segmented data must be formatted for use with existing software to render and view the cell(s) of interest. A "marching cubes" surface-rendering algorithm is often implemented in current visualization software, along with routines to view, rotate and scale the resulting surfaces in real time. The result of viewing and manipulating the biological data set will be an increased understanding of the processes of the fly's visual system. Other researchers will use the knowledge gained from the three-dimensional renderings of the cells to further develop an analog vision system based on the fly's compound eye. Much of this research is funded by the Navy Air Warfare Center in an effort to design an analog visual system with real-time target identification and tracking capabilities.

Animals↗