1. Architecture of a shared-image electronic whiteboard in telemedicine
Projekt INTER-FACE
Michael Fromme
Lehrgebiet Rechnernetze und Verteilte Systeme
Universität Hannover

2. Outline Conferencing scenarios in INTER-FACE
Network infrastructure in INTER-FACE
Whiteboard software and images
Architecture for whiteboard communication
System architecture and implementation
Conclusion
Michael Fromme

3. Project INTER-FACE Topic Aim
maxillofacial surgeries with bone rearrangements
computer-aided planning of the surgery
pre-operative treatment by orthodontists
multiple consultations of surgeon and orthodontist necessary
Aim
allow some consultations with the aid of a video conference
build a working environment for that case
evaluate working environment with respect to
efficiency
practical requirements
patient experience
Michael Fromme

4. Computer aided surgery planning
pre-surgery
post-surgery
Michael Fromme

5. Technical Equipment Orthodontist equipment
Video communication terminal (H.323)
PC with whiteboard
intra-oral camera
Michael Fromme

6. Communication structure
One or more specialists
at university hospitals
(Munich, Düsseldorf, or Stuttgart)
point-to-point or
multipoint conference
Orthodontist
(Munich)
H.323 MCU
(Hanover)
IWB Server
(Hanover)
Michael Fromme

7. Network infrastructure
GWiN
620 Mbps
Hanover
Munich
St. Augustin
H o s p i t a l s
decix / DFN
Düsseldorf
SDSL
1Mbps
Stuttgart
Orthodontists
(Munich)
Michael Fromme

8. Image Whiteboard functionality
Load and display common image formats
(TIFF, JPEG, BMP, FlashPix, PNG, PNM, GIF)
Image annotations
Image manipulations (zoom, pane, color effects)
Distribute and synchronize image and annotations
Use color management functionality
Session management
Print and save images
Michael Fromme

9. ICC Color Management Every device processes color in a different way
scanner
screen
computer
digital Kamera
printer
We need additional processing for a true reproduction of color.
This processing is done by a color management system.
Michael Fromme

10. Color Management screen profile scanner input profile screen computer
output profile
digital Kamera
printer
device dependend
color space
device independend
color space
device dependend
color space
Michael Fromme

11. Color Management in IWB
Features
uses color management facility of Java Advanced Imaging API
images can be loaded together with explicit input profile
images are distributed and processed in the device independent color space SRGB
Notes
need of accurate profiles for input / output devices, they can be generated with a spectral photometer and calibration software
many manufacturer provide profiles for their devices
Michael Fromme

12. IWB Network Communication
Multi-point conferences with IWB
IP multicast capable, but
works in IP multicast networks
only
TCP and central server needed for SDSL connected partners or partners behind firewalls
Multi-point protocol features
session handling
reliable transmission
startup syncronization (image bootstrap) with unicast
Michael Fromme

13. System architecture
Michael Fromme

14. Remote Object Invocation
Object method call
Object method call
Object serialization
Object de-serialization
transport connection
Request/Reply
Michael Fromme

15. ROI Transport Protocols
Unicast
TCP connection for reliable transport
UDP connections (variants: reliable, rate-limited)
Multicast
UDP (unreliable)
Lightweight Reliable Multicast Protocol LRMP (Inria)
Reliable Multicast Framework RMP (TASC)
Multicast simulation
transport connection is TCP from peer to server
central router component simulates unicast / multicast transmission
ROI Object Method Invocation Semantics
normal call (Unicast only)
one-way call
reliable group call with one return value (first value selected)
group call with return value array
Michael Fromme

16. Session Initiation Example
Michael Fromme

17. Conclusion Multi-user whiteboard Related information Further work
uses group-oriented middleware
based on Java Image API
Related information
{ german }
Further work
better adoption to the medical environment
integration for medical software (surgery planning)
user interface, input formats and functionality
security, e.g. encryption of network communication
Michael Fromme