Mixed Reality Needle Guidance Application on Smartglasses Without Pre-procedural CT Image Import with Manually Matching Coordinate Systems

AbstractFive important geodynamical quantities which are closely linked are: 1) motions of points on the Earth’s surface; 2)polar motion; 3) changes in UT1-UTC; 4) nutation; and 5) motion of the geocenter. For each of these we expect to achieve measurements in the near future which have an accuracy of 1 to 3 cm or 0.3 to 1 milliarcsec.From a metrological point of view, one can say simply: “Measure each quantity against whichever coordinate system you can make the most accurate measurements with respect to”. I believe that this statement should serve as a guiding principle for the recommendations of the colloquium. However, it also is important that the coordinate systems help to provide a clear separation between the different phenomena of interest, and correspond closely to the conceptual definitions in terms of which geophysicists think about the phenomena.In any discussion of angular motion in space, both a “body-fixed” system and a “space-fixed” system are used. Some relevant types of coordinate systems, reference directions, or reference points which have been considered are: 1) celestial systems based on optical star catalogs, distant galaxies, radio source catalogs, or the Moon and inner planets; 2) the Earth’s axis of rotation, which defines a line through the Earth as well as a celestial reference direction; 3) the geocenter; and 4) “quasi-Earth-fixed” coordinate systems.When a geophysicists discusses UT1 and polar motion, he usually is thinking of the angular motion of the main part of the mantle with respect to an inertial frame and to the direction of the spin axis. Since the velocities of relative motion in most of the mantle are expectd to be extremely small, even if “substantial” deep convection is occurring, the conceptual “quasi-Earth-fixed” reference frame seems well defined. Methods for realizing a close approximation to this frame fortunately exist. Hopefully, this colloquium will recommend procedures for establishing and maintaining such a system for use in geodynamics. Motion of points on the Earth’s surface and of the geocenter can be measured against such a system with the full accuracy of the new techniques.The situation with respect to celestial reference frames is different. The various measurement techniques give changes in the orientation of the Earth, relative to different systems, so that we would like to know the relative motions of the systems in order to compare the results. However, there does not appear to be a need for defining any new system. Subjective figures of merit for the various system dependon both the accuracy with which measurements can be made against them and the degree to which they can be related to inertial systems.The main coordinate system requirement related to the 5 geodynamic quantities discussed in this talk is thus for the establishment and maintenance of a “quasi-Earth-fixed” coordinate system which closely approximates the motion of the main part of the mantle. Changes in the orientation of this system with respect to the various celestial systems can be determined by both the new and the conventional techniques, provided that some knowledge of changes in the local vertical is available. Changes in the axis of rotation and in the geocenter with respect to this system also can be obtained, as well as measurements of nutation.

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2.2. Working Group 2: Conceptual Definitions of Reference Coordinate Systems for Earth Dynamics

International Astronomical Union Colloquium ◽

10.1017/s0252921100050867 ◽

1975 ◽

Vol 26 ◽

pp. 21-26

Keyword(s):

Coordinate System ◽

Working Group ◽

General Character ◽

Coordinate Systems ◽

Reference Coordinate System ◽

Group 2 ◽

Definition Of ◽

Earth Dynamics

An ideal definition of a reference coordinate system should meet the following general requirements:1. It should be as conceptually simple as possible, so its philosophy is well understood by the users.2. It should imply as few physical assumptions as possible. Wherever they are necessary, such assumptions should be of a very general character and, in particular, they should not be dependent upon astronomical and geophysical detailed theories.3. It should suggest a materialization that is dynamically stable and is accessible to observations with the required accuracy.

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Note on Selection of Coordinate Systems for Geodynamics

International Astronomical Union Colloquium ◽

10.1017/s0252921100051174 ◽

1975 ◽

Vol 26 ◽

pp. 395-407

Author(s):

S. Henriksen

Keyword(s):

Sea Level ◽

The Other ◽

Coordinate Systems ◽

Mean Sea Level ◽

The Earth ◽

The One ◽

Static Systems ◽

Selection Of

The first question to be answered, in seeking coordinate systems for geodynamics, is: what is geodynamics? The answer is, of course, that geodynamics is that part of geophysics which is concerned with movements of the Earth, as opposed to geostatics which is the physics of the stationary Earth. But as far as we know, there is no stationary Earth – epur sic monere. So geodynamics is actually coextensive with geophysics, and coordinate systems suitable for the one should be suitable for the other. At the present time, there are not many coordinate systems, if any, that can be identified with a static Earth. Certainly the only coordinate of aeronomic (atmospheric) interest is the height, and this is usually either as geodynamic height or as pressure. In oceanology, the most important coordinate is depth, and this, like heights in the atmosphere, is expressed as metric depth from mean sea level, as geodynamic depth, or as pressure. Only for the earth do we find “static” systems in use, ana even here there is real question as to whether the systems are dynamic or static. So it would seem that our answer to the question, of what kind, of coordinate systems are we seeking, must be that we are looking for the same systems as are used in geophysics, and these systems are dynamic in nature already – that is, their definition involvestime.

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The Role of VLBI in the Establishment of Coordinate Systems

International Astronomical Union Colloquium ◽

10.1017/s0252921100051083 ◽

1975 ◽

Vol 26 ◽

pp. 293-295 ◽

Cited By ~ 1

Author(s):

I. Zhongolovitch

Keyword(s):

General Solution ◽

Future Development ◽

Rational Approach ◽

Radio Telescopes ◽

Coordinate Systems ◽

Tectonic Plates ◽

Astronomical Observations ◽

Optical Instruments ◽

Fundamental Polyhedron

Considering the future development and general solution of the problem under consideration and also the high precision attainable by astronomical observations, the following procedure may be the most rational approach:1. On the main tectonic plates of the Earth’s crust, powerful movable radio telescopes should be mounted at the same points where standard optical instruments are installed. There should be two stations separated by a distance of about 6 to 8000 kilometers on each plate. Thus, we obtain a fundamental polyhedron embracing the whole Earth with about 10 to 12 apexes, and with its sides represented by VLBI.

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Effects of Using Mixed Reality With Coaching on the Interprofessional Communication Skills of Speech-Language Pathology Graduate Students

Perspectives of the ASHA Special Interest Groups ◽

10.1044/2020_persp-20-00098 ◽

2021 ◽

pp. 1-21

Author(s):

Jacqueline A. Towson ◽

Matthew S. Taylor ◽

Diana L. Abarca ◽

Claire Donehower Paul ◽

Faith Ezekiel-Wilder

Keyword(s):

Graduate Students ◽

Self Efficacy ◽

Mixed Reality ◽

Role Play ◽

Speech Language Pathology ◽

Traditional Role ◽

Allied Health Professionals ◽

Interprofessional Communication ◽

Language Pathology ◽

The Individual

Purpose Communication between allied health professionals, teachers, and family members is a critical skill when addressing and providing for the individual needs of patients. Graduate students in speech-language pathology programs often have limited opportunities to practice these skills prior to or during externship placements. The purpose of this study was to research a mixed reality simulator as a viable option for speech-language pathology graduate students to practice interprofessional communication (IPC) skills delivering diagnostic information to different stakeholders compared to traditional role-play scenarios. Method Eighty graduate students ( N = 80) completing their third semester in one speech-language pathology program were randomly assigned to one of four conditions: mixed-reality simulation with and without coaching or role play with and without coaching. Data were collected on students' self-efficacy, IPC skills pre- and postintervention, and perceptions of the intervention. Results The students in the two coaching groups scored significantly higher than the students in the noncoaching groups on observed IPC skills. There were no significant differences in students' self-efficacy. Students' responses on social validity measures showed both interventions, including coaching, were acceptable and feasible. Conclusions Findings indicated that coaching paired with either mixed-reality simulation or role play are viable methods to target improvement of IPC skills for graduate students in speech-language pathology. These findings are particularly relevant given the recent approval for students to obtain clinical hours in simulated environments.

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