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

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

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

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

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

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

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

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

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

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

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

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

System architecture Michael Fromme

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

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

Session Initiation Example Michael Fromme

Conclusion Multi-user whiteboard Related information Further work uses group-oriented middleware based on Java Image API Related information http://www.rvs.uni-hannover.de/projects/interface { german } http://www.rvs.uni-hannover.de/products/iwb 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