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ITG Forum. Constructing a Research Grade Interactive Remote Microscopy Application: Goals, Challenges, and Results . Don Appleman, Visiting Research Programmer , Imaging Technology Group. April 1, 2003. ITG Mission. Mission of the Imaging Technology Group

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ITG Forum

Constructing a Research Grade Interactive Remote Microscopy Application:

Goals, Challenges, and Results

Don Appleman, Visiting Research Programmer, Imaging Technology Group

April 1, 2003


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ITG Mission

Mission of the Imaging Technology Group

  • Provide state-of-the-art imaging facilities for Institute researchers.

  • Develop advanced imaging technologies with emphasis on projects in remote and automated instrument control.


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Remote Instrumentation

Remote access to imaging instrumentation

Why?

  • Unique and/or expensive instrumentation

  • Distributed expertise

  • Outreach; Education; Training of professional researchers and engineers


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What is Bugscope?

What is Bugscope?

  • Web-based access to an Environmental Scanning Electron Microscope (ESEM) for K-12 classrooms to image “bugs”.

  • Schools in 33 states have used the ESEM over the Internet in more than 120 sessions using the current software.


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Current Technology

Initial Implementation

  • Separate Controller & Observer software

  • Chat Window for conversing with microscopist

  • Java applets or CGI interface to microscope server software

  • Still images only



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Current Technology

Drawbacks

  • Still images only

  • Time to acquire image is long

    This results in the following problems …

  • Difficulty navigating across the sample

  • Difficulty focusing

  • Loss of concentration on the task at hand


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Current Technology

Current Project

  • The current project is a remote instrumentation project funded by NASA.

  • NASA is interested in the remote operation of complex scientific equipment over long distances in real time.

  • The project goal is to enhance the Bugscope software, known as the Interactive Remote Microscopy Application (IRMA), to the point where it qualifies as a research-grade interface.


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Future Technology

Approach — Improved Input & Output

  • Input — Sufficient control of the microscope

    +

  • Output — True-to-life viewing experience

    =

    Goals

  • Remote and collaborative research among isolated researchers

  • Training new users to operate the ESEM

  • Teaching classes ranging from nanoscience to biology


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Future Technology

Proposal

  • Add streaming video to Bugscope


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Future Technology

Proposal

  • Add streaming video to Bugscope

    Challenges

  • Bandwidth requirements

  • Image quality

  • Image latency

  • Image size


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Streaming Video

For a given bandwidth capacity, pick any two

  • Image quality

    Fidelity of the reconstructed image to the original source

  • Image latency

    Delay in real-time between acquisition of the image and display of the image to the remote user

  • Image size

    The size of the image displayed to the remote user


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Streaming Video

Videocast options

  • Broadcast

    • Video stream sent to everyone on a limited network.

    • Server bandwidth equivalent to a single stream.

    • Creates lots of network traffic.

    • Not compatible with Internet delivery to arbitrary users.

  • Unicast

    • Dedicated video stream sent to a single, known client.

    • Serves a single client.


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Streaming Video

Videocast options, cont’d

  • Multi-unicast

    • Multiple dedicated video streams sent to multiple clients.

    • Server bandwidth multiplied by number of simultaneous users.

    • Client bandwidth multiplied by number of simultaneous users on given Internet feed (classroom full of students).

  • Multicast

    • Video stream sent to abstract address, replicated by routers.

    • Server bandwidth equivalent to a single stream.

    • Client bandwidth equivalent to a single stream for Internet feed.

    • Requires properly configured, compatible routers.


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Streaming Video

Videocast solution

Hybrid Video Server

  • Initiate multicast

  • Listen for client connections

  • Inform clients of the active multicast address

  • If the client reports that it cannot see the multicast

    • Start a dedicated unicast to client address

    • Inform client of unicast address:port

    • Monitor client status


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Streaming Video

Project-specific Advantages

  • No audio

  • Monochromatic source

    The solution

  • H263 video-conferencing video format

  • Video server written in Java (using Java Media Framework)

  • Java applet video client (adjunct to extant software)


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Streaming Video

Project-specific Results, low bandwidth

  • Video stream bandwidth ~100Kbps

  • Image quality acceptable (some quality lost, still image needed for actual study); good enough for fine focus control using current interface

  • Image latency less than or equal to 500 ms

  • Image size 352x288

  • Video frame rate ~15 frames per second (variable bit rate)


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Streaming Video

Project-specific Results, high bandwidth

  • Video stream bandwidth ~3Mbps

  • Image quality very good (JPEG quality 0.8, still image usually not needed for actual study)

  • Image latency less than or equal to 500 ms

  • Image size 640x480

  • Video frame rate ~15 frames per second (variable bit rate)


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Beyond Video

A new, more complete and more natural user interface.

Expose the majority of the controls accessible when using the ESEM directly.


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Beyond Video

New controls

  • Beam on/off, kV, and spot size

  • Scan mode (Slow scan 1, 2, 3, or TV mode)

  • Filters (Live, Integrate 1, Average 4)

  • Detectors (Secondary electron, Backscatter electron, CCD camera)

    Improved controls

  • New Navigation, Focus, and Measurement Tools


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Beyond Video

Not all controls can be included

  • Cannot change specimens

  • Cannot activate vacuum

  • Cannot operate manual tilt mechanism

    An operator is required to prepare and mount the specimen, and to activate the vacuum.


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Navigation Tool

ESEM Navigation

Click anywhere relative to the green overlay circle, and the stage will move in that direction.

In “TV” mode, click & hold moves smoothly in given direction.


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Navigation Tool

  • Bugscope Navigation

  • Control+click on Observer to center image on selected location

  • Controller stage control

  • Controller presets


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Navigation Tool

Proposed Navigation

  • Click & hold over video window to move as if in “TV” mode on ESEM

  • Keyboard or other control to move by ½ screen in any direction

  • Control+click on video display to center image on selected location


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Focus Tool

ESEM Focus

Click & drag right mouse button left/right to increase/decrease focus distance.

Control+click & drag right mouse button left/right or up/down to adjust stigmator x,y.


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Focus Tool

  • Bugscope Focus

  • Coarse control +/- to adjust focus by 1mm

  • Fine control to adjust by 0.1mm to 0.9mm

  • ESEM Auto Focus (slow, can be unreliable)


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Focus Tool

Proposed Focus (same as ESEM focus)

  • Using video window, click & drag right mouse button left/right to increase/decrease focus distance.

  • Using video window, control+click & drag right mouse button left/right or up/down to adjust stigmator x,y.

  • May also use trio of images, side by side, each showing a different focal depth that the user can select.


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User Base

Varying user base

  • Educational Outreach (Bugscope)

    • Bandwidth limited (usually)

    • Little or no experience operating a real ESEM

    • Not fully accountable

    • Chat with professional required

  • Professional Researchers

    • Lots of bandwidth (usually)

    • May have experience operating a real ESEM

    • Higher level of accountability

    • Professional assistance unneeded


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User Base

Varying user base, solution

Configurable control set

  • For educational outreach, eliminate controls that are confusing, hard to use, or which might damage the equipment.

    Configurable video server

  • Configure to use available bandwidth


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Conclusions

Conclusions:

  • With the addition of streaming video to Bugscope, the issue of realism for the output of the IRMA software has been addressed.

  • Once we complete the enhancements to the input interface of the Controller, IRMA will be a true, research-ready option for usage of the ESEM.

  • With the requirement that an operator be present to prepare and mount the specimens, and to operate the vacuum controls, IRMA will remain limited.

  • As a proof-of-concept of remote instrumentation capabilities, the completed project is a success.


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References

The Bugscope web site

http://bugscope.beckman.uiuc.edu

Technical reports

http://bugscope.beckman.uiuc.edu/publications/index.htm


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