Evaluation of IP Video Technologies for Telemedicine: The East Carolina University Experience
Scott C. SimmonsDirector, Design & DevelopmentECU Telemedicine Center
Overview
• ECU Telemedicine Center Overview• Internet Telemedicine• NIH/NLM Biomedical Applications of
the NGI• Testing CODEC/Network Performance• Lessons Learned• Future Directions
ECU Telemedicine Center
• Links patients to physicians, MD-to-MD, hospital to hospital
• Over 8,000 consults since 1991• Hospitals, clinics, homes• 14,000 square mile service
area• 32 clinical specialties• Distance Learning and Grand
Rounds• Virtual Surgery (DaVinci)
Internet Telemedicine• IP videoconferencing (H.323, MPEG)• Use of PC’s and Internet for asynchronous
consults, i.e. “store-and-forward” • Other capabilities
– telemetry of data– electronic mail with attachments– file transfer– whiteboarding– application sharing– chat
IP Collaboration Technologies
• Can use existing IP infrastructure?
• Different technologies– H.323– MPEG-1, 2, (4)– Access Grid
Biomedical Applications of the Next Generation Internet (NGI)
• NLM (NIH) initiative for “innovative medical projects that demonstrate the application and use of NGI capabilities:– Quality of service– Medical data privacy and security– Nomadic computing– Network management– Infrastructure technology for scientific
collaboration”
ECU TM Center NLM Contract
• ECU Telemedicine Center awarded 3-year, $4.6 M contract for “Internet Protocol Telemedicine and Pediatric Cardiology Education” (N01-LM-9-3541)– IP telemedicine (10 specialties)– Store-and-forward cineangiograms– Electromyography– Pediatric cardiology education– Microwebservers
Testing CODEC & N/W Performance
• First test in lab, then in Eastern NC network
• SMPTE time code – dropped video frames• Video test equipment – objective video
quality• Clinical opinion of diagnostic quality
using “gold standard” sources
Advertised vs. Actual FPSCLI @ 768 (H.320) = 29 fps
14.5MIN INON TAPE CLI
FRAMES 768
1 12 23 34 45 56 67 78 89 9
10 911 1012 1213 13
VCON @ 768 (H.323) = 14 fpsON TAPE 8.5MIN IN
VCON @768
FRAMES
1 32 53 54 55 86 87 108 109 11
10 1311 1312 1613 1614 1715 1716 1917 19
Advertised vs. Actual FPS (cont’d)
Proshare @ 400 (H.323) = 15 fps Polycom @ 768 (H.323) = 26 fps
OnTape PROSHARE@ 400
FRAMES
1 12 13 34 35 56 57 78 79 7
10 911 1112 1113 1114 1315 1516 1517 17
ON TAPE POLYCOMVIEWSTATION
FRAMES 768
1 12 33 44 55 66 77 88 89 9
10 1011 1212 1313 1314 1515 1516 1617 18
Video Testing
SMPTE Color Bars – Waveform SMPTE Color Bars – Vectorscope
Luminance 5 Step Multiburst 100
Video Testing Setup
Hub
Codec Codec
Test Generator
AV Router
AV Router
Time Code Gen
Test Pattern
Test Pattern + Time code
WFM/Vectscope
HI 8VCR
<Show Video Tests>
Audio Testing – White Noise
Polycom
Minerva Vbrick
Audio Testing – Stethoscope
Polycom
Minerva Vbrick
Physician Assessment of Dx Quality
• Gold standard DV tapes developed in 10 specialties: Adult Cardiology, Allergy, Dermatology, Endocrinology, Obstetrics, Pediatric cardiology, Psychiatry, Pulmonology, Rehabilitation Medicine, Trauma
• Tapes played through codecs with different network (bandwidth) settings
• Three physicians/specialty assessed point at which video/audio was unusable for Dx
• Results used to select codecs for regional network
Physician Assessment Test N/W
Findings from Physician Assessment
• Polycom best H.323• Vbrick best MPEG • 7 video packet/minute loss threshold for
diagnosis• H.323 manages lost audio by repeating –
this can sound like cardiac anomaly• Similarly, crackles (lung sound) can be lost• MPEG best for clinical audio (heart & lung
sounds)
• IP networks not designed/optimized for videoconferencing
• Technical issues:– Congestion/packet loss– Variable bit rate– Security– Directory services– IP multicast
• Latency is 250+ ms w/o network with current videoconferencing products
IP Telemedicine Challenges
• Overprovision your network• Implement quality of service mechanism
– Works within your network/campus• Reduce inherent latency associated with
digitization/encoding• Avoid/eliminate bottlenecks
– Hubs– Routers (use non-blocking wire-speed switches
instead)– Firewalls– 802.11
How to Address IP Challenges
• Conduct regional assessment in 45 Mbps wireless network
• Study reverse of initial lab study to look for correlation (i.e. worst-to-best)
• Evaluate line-speed encryption technologies• Examine new software-only videoconferencing
system from TeraMedia & Tulane University Bioinformatics
• Pilot testing of H.323 to homes connected by cable and xDSL service
Future Directions
Regional Wireless Network Overview
BethelRepeater
WIlliamstonRepeater
WIndsorRepeater
AhoskieRepeater
ECUTelemedicine
Center
BertieMemorialHospital
Roanoke/Chowan Hospital
12.6 mi.
16.3 mi.
12.8 mi.
22.5 mi. 1.9 mi.1.1 mi.
(Diagram not to scale)
All radio links 45 Mbps full duplex
Proposed Router
Radio tower
Existing CHSC Switch
GE 99Router
Radio tower
L3 Switch Ahoskie
L3 Switch WindsorRadio tower
School for the Deaf
Cherry Hospital
Tarboro
Duplin
Onslow
Health East 1
Health East ??
T1's from remote sites
Radio tower
Future IP Telemedicine Network
Contact Information
Scott C. SimmonsDirector, Design & DevelopmentECU Telemedicine Center600 Moye Blvd., 1S-10Greenville, NC 27858-4354(252) [email protected]
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