Device Description Research Articles

Hemodynamic Effects of Simultaneous Sterno-Thoracic Cardiopulmonary Resuscitation (SST-CPR) in Canine Model of Cardiac Arrest

Background and Objectives:No existing device for cardiopulmonary resuscitation (CPR) is designed to exploit both the “cardiac pump” and the “thoracic pump” simultaneously. This study was designed to assess the hemodynamic effects of simultaneous sterno-thoracic CPR (SST-CPR) vs. standard CPR (S-CPR) using a mechanical resuscitator in a canine model of cardiac arrest. Device Description:We have built a device that depresses the sternum and circumferentially constricts the thorax simultaneously. This device has two components. The first component is a piston, which depresses the sternum. The second is a circumferential strap that constricts the thorax as the piston is pushed down on the sternum. Materials and Methods:Twelve domestic dogs were enrolled in this study. After catheterizations to measure pressures from the aorta and the right atrium, ventricular fibrillation was induced by passing AC current to the right ventricle. After 4 minutes of cardiac arrest, S-CPR and SST-CPR were performed alternatively. Aortic pressure, right atrial pressure, cardiac output, and end tidal CO2 were measured while each method of CPR was performing. Results:SST-CPR resulted in significantly higher mean arterial pressure than S-CPR (68.9±16.1 vs 30.5±10.0 mmHg, p<0.01). SST-CPR could generate higher coronary perfusion pressure than S-CPR (47.0±11.4 vs 17.3±8.9 mmHg, p<0.01). End tidal CO2 tension was also higher during SST-CPR than S-CPR (11.6±6.1 vs 2.17±3.3 mmHg, p<0.01). Conclusion:Simultaneous sternothoracic cardiopulmonary resuscitation is a new method of cardiopulmonary resuscitation, which can generate better hemodynamic effects than standard cardiopulmonary resuscitation. (Korean Circulation J 1999;29(10):1105-1111)

Design of a PZT-actuated proportional drum brake

Presents the design of a piezoelectric-ceramic (PZT)-stack-actuated brake that is similar to a magnetic particle brake in dynamic range, size, weight, and cost, while providing a significantly larger bandwidth and requiring significantly less electrical power for a given continuous torque output. The device is essentially a single-pad drum brake that is actuated with a PZT-stack actuator. A significant component of the design is the compliant-mechanism-based transmission utilized to transmit the PZT-stack actuation into brake pad motion. Following the device description, experimental data is presented to characterize the performance of the brake. The performance characteristics are subsequently compared to those of a commercially available magnetic particle brake of comparable size and weight.

Turning pervasive computing into mediated spaces

With pervasive computing, we envision a future in which computation becomes part of the environment. The computer forms (workstation, personal computer, personal digital assistant, game player) through which we now relate to computation will occupy only a small niche in this new computational world. Our relationship to pervasive computing will differ radically from our current relationship with computers. When computation becomes part of the environment, most human-computer interaction will be implicit, and it will have to take account of physical space. Physical space rarely matters in current human-computer interaction; but as computational devices become part of furniture, walls, and clothing, physical space becomes a necessary consideration. First, more than one person can occupy a space. Second, individuals within the space are doing things other than interacting with the computer: coming and going, and perhaps most strikingly, interacting with each other—not just with the computer. Finally, phy sical space provides a sense of place: individuals associate places with events and recurrent activities. The emerging relationship between people and pervasive computation is sometimes idealized as a “smart space”: the seamless integration of people, computation, and physical reality. This paper focuses on a particular kind of smart space, the “mediated space,” in which the space understands and participates in multiperson interaction. Mediated spaces will expand human capability by providing information management within a context associated with that space. The context will be created by recording interaction within the space and by importing information from the outside. Individuals will interact with the space explicitly in order to retrieve and analyze the information it contains, and implicitly by adding to the context through their speech and gesture. Achieving the vision of mediated spaces will require progress in both behind-the-scenes technology (how devices coordinate their act ivities) and at-the-interface technology (how the space presents itself to people, and how the space deals with multiperson interaction). This paper explores the research challenges in both of these areas, examining the behind-the-scenes requirements of device or manifestation description and context maintenance, as well as the interface problems of metaphor and understanding natural human-to-human spoken interaction.

A complete testing strategy based on interacting and hierarchical FSMs

Control-dominated devices are usually modeled as a composition of finite state machines. FSMs can be hierarchically composed to dominate the modeling complexity or can be aggregated into an interacting architecture to partition a complex behavior. A hierarchical or interacting FSM based representation can be extracted from a device's description given by means of a hardware description language. The core of the paper concerns the definition of a complete testing strategy based on the comparison between these FSMs' representations and the structural representations of the device. This comparison simplifies the testing problem by using the functional information to perform scan insertion, redundancies removal and test pattern generation considering the actual stuck-at fault model on the gate-level implementation. Therefore, a fully testable implementation can be thus obtained even for such devices which cannot be satisfactorily analyzed at the gate level.

A new white light photosedimentometer for solid-liquid dispersion study: device description, stability and settling behaviour

This paper describes a new photosedimentation device that monitors and measures the settling rate, hindered settling, constant, flocculation factor, sediment volume and rate of coagulation of monodisperse samples of solid particulates in dispersant liquids. First we examine the well-known theoretical aspects of sedimentation as well as some sedimentation and turbidity applications. Then we introduce the K200 photosedimentometer and most of its technical features and advantages with respect to existing devices. Finally, we give the results of several turbidimetric (particle size modification, concentration determination) and settling measurements (stability parameters).

Undulators at the Advanced Light Source

At Lawrence Berkeley Laboratory’s Advanced Light Source, three 4.6 m long undulators have been completed, tested, and installed. A fourth is under construction. The completed undulators include two 5.0 cm period length, 89 period devices (U5.0s) which achieve a 0.85 T effective field at a 14 mm minimum gap and a 8.0 cm period length, 55 period device (U8.0) that reaches a 1.2 T effective field at a 14 mm minimum gap. The undulator under construction is a 10.0 cm period length, 43 period device (U10.0) that is designed to achieve 0.98 T at a 23 mm gap. Undulator magnetic gap variation (rms) is within 25 μm over the periodic structure length. Reproducibility of the adjustable magnetic gap has been measured to be within ±5 μm. Gap adjusting range is from 14 to 210 mm, which can be scanned in 1 min. The 5.1 m long vacuum chambers are flat in the vertical direction to within 0.74 mm and straight in the horizontal direction to within 0.08 mm over the 4.6 m magnetic structure sections. Vacuum chamber base pressures after UHV beam conditioning are in the mid-10−11 Torr range and storage ring operating pressures with full current are in the low 10−10 Torr range. Measurements show that the uncorrelated magnetic field errors are 0.23% and 0.20% for the two U5.0s and the U8.0, respectively, and that the field integrals are small over the 1 cm×6 cm beam aperture. Device description, fabrication, and measurements are presented.

Understanding ventricular assist devices: a self-study guide.

Considerable progress has been made over the past several decades in development of ventricular assist device (VAD) technology. Initially, failure to wean from cardiopulmonary bypass was the primary indication for VAD support. However, VAD role has expanded to include patients with ventricular failure due to myocardial infarction and patients awaiting cardiac transplantation. A greater number of nurses, both in the intensive care and general floors, are required to care for patients supported with VADs. Therefore, a self-study guide was developed to facilitate learning. Heart failure physiology, mechanical device descriptions, patient selection, potential complications, and nursing care of patients who require VAD support are reviewed.

Evaluation of the performance characteristics of a thermal transient anemometer

This paper describes and evaluates a thermal transient anemometer, a novel fluid flow (mass flux) measuring device having a thermocouple probe which is utilized to measure the change in temperature over a period of time to provide a measure of fluid flow velocity. The thermocouple probe (sensor) is periodically heated by the application of an electrical pulse and its rate of cooling between pulses is related to the local mean flow velocity. The theory of operation, device description, comparison with other similar fluid flow devices, and laboratory tests including measurements under different turbulence levels and different fluid temperatures are presented and discussed.

Internalizing and the Use Specificity of Device Knowledge

Four experiments were performed to test the relationship between instructionally derived knowledge and practice in the use of a simple device. Using a derivative of Kieras and Bovair's (1984) device, we show that different subjects can be given instructions that convey equivalent information but that lead to crossovers in the time to perform different tasks (i.e., one task is easier with one set of instructions, a second task is easier with other instructions). Experiment 1 shows that the performance crossover between question types perseveres when subjects relinquish the instructions, after they have been committed to memory. Experiment 2 shows that the performance crossover perseveres over considerable experience using the device. Experiment 3 shows that the crossover can disappear if sufficient practice is given with the particular question types. Experiments 2 and 3 taken together suggest that subjects may only be able to overcome the computational disadvantages of their initial instructional material by adopting task-specific strategies. Experiment 4 shows that when new problems are introduced after the point at which the crossover disappears then a new crossover appears, implying that, even with extended practice of operating the device and solving problems on the device, some features of the initial instructional device description are preserved and continue to determine the users' behavior. We argue that a definition of internalization coupled with Anderson's (1983, 1987) ACT* theory of skill acquisition provides a good account of these results.

Implementation of a mask verification language and its compiler

The paper describes the design and philosophy of a mask verification language (MVL) and its compiler. Mask verification tools have to be programmable, because of the large software investment they require, and the speed at which fabrication technology changes. The language described here allows a designer to specify the topological structure of a device (the device description), and to attach to it a procedure to be executed when that device is recognised (the device procedure). The device procedure allows certain geometric qualifications to be placed on the structure. (The device description and procedure, taken together, form a device declaration.) In general, an MVL program will contain several device declarations: one for each realisable type of device of a technology. The description part of a declaration is asynchronous, and the procedural part, which is internally sequential, is executed once for each instance of the device description located on the mask set. Careful choice of the primitives provided allows extensive optimisation of the leaf operations involved, which is extremely important, given the usual size of the mask data-sets.

Design of a language for IC mask verification and net extraction

The paper describes the design of a language (the Mask Verification Language, or MVL) to interface with a programmable mask analysis system to check technology rules and extract netlists in a low-cost computing environment. The system operates in batch mode, i.e. mask designs are presented to the system, which checks them and reports errors. If there are problems, the mask designer can re-enter the mask editor to correct them. Running on a single-user workstation, the development loop has been found to be very fast. Legal devices and the technology description are presented to the system in MVL. Each device description contains a descriptive part which controls how a device is recognised, and a procedural part which controls how it is verified and processed once it has been recognised. As the programmer has no control over the order in which the descriptive sections are processed, it is possible for the system to optimise the mask operations necessary to perform the design rule checks and extract the circuit. The system is in regular use in a research environment, where design rules are not as inviolate as in industry. It has been used to encode the rules for I2L, NMOS and CMOS circuits, and can extract parasitic estimates as well as topological circuits.

Electrochromic displays

The fabrication and behaviour of large-area electrochromic displays based upon lithium atom insertion into tungsten trioxide is discussed. The device description is preceded by an outline review of the essential physical phenomena involved.

Explanation-based learning for knowledge-based systems

We discuss explanation-based learning for knowledge-based systems. First, we identify some potential problems with the typical means of acquiring a knowledge base: interviewing domain experts. Next, we review some examples of knowledge-based systems which include explanation-based learning moduluses and discuss two systems in detail: ACES ( Pazzani, 1986 a ) which learns heuristics for fault diagnosis from device descriptions, and OCCAM ( Pazzani, 1986 b ) which learns to predict the outcome of economic sanction episodes from simple economic theories. We conclude that explanation-based learning is a promising approach to constructing knowledge-based systems when the required information is available but not in the form of heuristic rules. In this case, the role of explanation-based learning is to explicate heuristics which are only implicit in deep models.

A software tool for microprocessor functional test

BAT (Behavioral Automatic Tester) is a software tool written in C programming language and running in a UNIX enviroment providing the user of a self-contained package for a programmable device's behavioral test. An editor allows the user to describe the device from a behavioral point of view. The device's description is then translated into functional relationships between instructions and then modeled by means of a Petri net. Final goal is to obtain the optimum test sequence for the considered device. First steps in implementation are presented. Definition of a behavioral description language, editor specifications, data storage management and error recovery routines are inspected.

Representing Structure and Behavior of Digital Hardware

The development of expert systems for troubleshooting digital electronics is considered. It is shown that suitably represented descriptions of structure and behavior set an important foundation. The authors approach offers a unity of device description and simulation, since the descriptions themselves are runnable. Unsolved problems are noted. 10 references.

Preschool Activity Level: Personality Correlates and Developmental Implications

Buss, DAVID M.; BLOCK, JEANNE H.; and BLOCK, JACK. Preschool Activity Level: Personality Correlates and Developmental Implications. CmLD DEVELOPMENT, 1980, 51, 401-408. Activity level was measured by 2 independent methods, a mechanical recording device and teacher descriptions, in a sample of 129 children (65 boys and 64 girls), participating in an ongoing longitudinal study. 3 independent actometer measures were taken at age 3, and 4 independent measures were taken at age 4. Separately, personality data were collected on these children at ages 3, 4, and 7 from independent sets of teachers using the California Child Q Set (CCQ). The first study examined the cross-method and cross-time consistency of activity level. The actometer-based and teacher-based activity level scores correlated substantially, providing reciprocal validation for both methods of assessing activity level. Cross-time correlations indicated activity level remains fairly consistent, both within the preschool years and across a 4-year time span. The second study examined the relationship between a preschool actometer index and independently derived personality variables at ages 3, 4, and 7. Results indicated that preschool activity level related substantially to a set of interpersonal attributes as well as to an expected set of motoric attributes. A core set of these activity level relationships was found at all 3 ages. Implications for the developmental stability of some features and the interrelationships among different domains of functioning were discussed.

A coincident-select MOS storage array

Utilization of MOS monolithic storage arrays in random access memory offers low cost with high performance. An approach is described using a 64-bit coincident-select MOS storage device as the fundamental building block to achieve the low-cost high-performance goals. Device and circuit descriptions as well as cross-talk models are discussed.