Blind deep venous puncture is an invasive procedure with risks of serious complications compromising the availability of veins for future punctures or endangering the patient's life. We designed a new hand-held pu...
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Blind deep venous puncture is an invasive procedure with risks of serious complications compromising the availability of veins for future punctures or endangering the patient's life. We designed a new hand-held pulsed Doppler probe for coaxial guidance of the puncture needle and a dedicated pulsed Doppler device displaying the depth of the measurement volume. We used this technique prospectively in two independent centers (the nephrology department and the intensive care unit) involving senior as well as junior staff members. Either the non-Doppler or the Doppler method were randomly selected for subclavian vein catheterization in 100 patients and for internal jugular vein catheterization in 30 patients. The success rate on the first attempt was 86.2% for the non-Doppler method versus 96.8% for the Doppler method (p = 0.03). The failure rate of the non-Doppler method used by junior staff members was 9.2%, reduced to 1.5% (p = 0.05) by secondary use of the Doppler method and/or help from a senior staff member (rescue procedure). Pulsed Doppler guidance reduced significantly the failure rate of venous punctures especially when used by seniors or by juniors after a training period.
It is shown that the optimal guidance problem can be handled as a Bolza-type problem which can be solved by straightforward calculation The solution proves to be different from that given by Yang, et al. and is verifi...
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It is shown that the optimal guidance problem can be handled as a Bolza-type problem which can be solved by straightforward calculation The solution proves to be different from that given by Yang, et al. and is verified to be a minimum performance index solution. Also presented is an alternate unified approach to the solution of the nonlinear system of differential equation of the generalized proportional navigation law discussed earlier by Yang, et al. This unified equation has been solved for all the different cases of proportional navigation for which closed-form solutions have been published by earlier authors.
This paper presents an integrated approach to the problem of AGV guidance using trinocular vision. Although this method uses three cameras, we will not do any processings related to stereo matching nor 3-D reconstruct...
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This paper presents an integrated approach to the problem of AGV guidance using trinocular vision. Although this method uses three cameras, we will not do any processings related to stereo matching nor 3-D reconstruction. Instead, our trinocular vision is divided into two subsystems: monocular vision for path localization and binocular vision for obstacle detection. First, we demonstrate the geometric principle of 2-D vision. Then, we show its application for the task of AGV's path localization as well as the task of AGV's obstacle detection in the framework of trinocular vision. Experimental results with real images prove the usefulness of our method.
The Global Positioning System (GPS) satellites provide positioning information which can be of significant use for agricultural applicators. This article presents the results of a quantitative evaluation of the precis...
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The Global Positioning System (GPS) satellites provide positioning information which can be of significant use for agricultural applicators. This article presents the results of a quantitative evaluation of the precision of a commercial device which incorporates differentially corrected GPS signals (DGPS) to guide a ground vehicle along swaths. The precision of the cross-track displacement along the swath is determined with a video camera verification system and the results have been analyzed statistically.
We study multi-stream networks in which feature discovery and associative learning interact cooperatively at the level of the local processors. These processors select and recode the information in their receptive fie...
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We study multi-stream networks in which feature discovery and associative learning interact cooperatively at the level of the local processors. These processors select and recode the information in their receptive field (RF) inputs that is predictably related to the context within which it occurs. To enable them to do this they are provided with local contextual input in addition to their receptive field input. This input guides both learning and processing to the RF information that is related to the context, but without confounding the information that the processor transmits about the RF. We show that these nets can discover linear functions of their inputs that are predictably related across streams. They can do so whether or not these variables are the most informative within streams, and when there is no evidence within streams as to the existence of these variables. They discover the relevant variables concurrently with, and because of, discovering the predictive relations between them. Two-stage multi-stream nets can discover the XOR function when the only evidence for it is in the higher-order cross-stream statistical dependencies, and when there are no pair-wise correlations in the input either within or across streams. This problem is at the limits of the ability of these nets, however, and they do not always solve it. Various aspects of these limitations are studied. Overall the results show that performance improves as the number of streams increases, and this encourages the view that the approach may have biological relevance.
作者：
HOWARD, RTBOOK, MLNASA
GEORGE C MARSHALL SPACE FLIGHT CTRORBITAL SYST & ROBOT BRANCHEB62HUNTSVILLEAL 35812
The Video guidance Sensor (VGS) has been developed by NASA's Marshall Space Flight Center (MSFC) to provide the capability for a spacecraft to find and track a target vehicle and determine the relative positions a...
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ISBN:
(纸本)0819418196
The Video guidance Sensor (VGS) has been developed by NASA's Marshall Space Flight Center (MSFC) to provide the capability for a spacecraft to find and track a target vehicle and determine the relative positions and attitudes between the sensor and the target. The sensor uses laser diodes to illuminate the target, a CCD-based camera to sense the target, and a frame-grabber and processor to convert the video information into relative range, azimuth, elevation, roll, pitch, and yaw. The sensor was first built in 1988 and used in successful automated docking experiments using the air-bearing spacecraft simulator in MSFC's Flight Robotics Laboratory. Since then, many changes and improvements have been made, based on the results of testing. In addition to the use of this system for space vehicles, it has been adapted for commercial application. The current design is being built as a prototype to prepare for flight testing on the Space Shuttle. Some of the changes from the original system were designed to improve the noise rejection of the system. Other changes were made to improve the overall range of operation of the system, and still other changes improved the bandwidth of the system. The current VGS is designed to operate from 110 meters down to 0.5 meters and output the relative position and attitude data at 5 Hz. The system will be able to operate under any orbital lighting conditions from full solar illumination to complete darkness. The VGS is also designed to be used with more than one target and sensor to allow for redundant configurations. This new prototype should be completed and undergoing open- and closed-loop testing after March 1995.
A divertor magnetic configuration is proposed that significantly reduces heat load on the divertor plates in heliotron/torsatron devices. The proposed configuration utilizes an octapole field for guiding the divertor ...
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A divertor magnetic configuration is proposed that significantly reduces heat load on the divertor plates in heliotron/torsatron devices. The proposed configuration utilizes an octapole field for guiding the divertor channels to a remote area outside the mail coil system, where the magnetic field is weak. This allows a significant reduction of the heat load due to expansion of the divertor channels as well as substantially easier access to the divertor plates for maintenance, the key requirements for toroidal fusion reactor designs.
Percutaneous pericardial catheter drainage with ultrasound guidance is the standard techniquefor emergency relief of cardiac *** performed urgent CT-guided percutaneous pericardialdrainage in two patients.A 5F pigtail...
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Percutaneous pericardial catheter drainage with ultrasound guidance is the standard techniquefor emergency relief of cardiac *** performed urgent CT-guided percutaneous pericardialdrainage in two patients.A 5F pigtail catheter was placed in the pericardial space by a trocar *** procedure was effective and well *** complications occurred and no recurrence of pericardialeffusion was observed.
Discusses the importance of humanistic and modernistic views of identity in the practices of guidance and counselling of adult learners. Concept of guidance and its centrality to learning process; Market models in the...
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Discusses the importance of humanistic and modernistic views of identity in the practices of guidance and counselling of adult learners. Concept of guidance and its centrality to learning process; Market models in the conception of guidance; Humanistic discourse of guidance and counselling; Notion of confession; Differing views of modern and postmodern identity.
The Schoot-to-Work Opportunities Act will inevitably change the face of public education. It will force school districts to re-evaluate their priorities and regard every member of the community as a student, making li...
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The Schoot-to-Work Opportunities Act will inevitably change the face of public education. It will force school districts to re-evaluate their priorities and regard every member of the community as a student, making lifelong learning the goal of every school. It will also change expectations regarding the role of school guidance counselors.
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