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) 816-3852simmonss@mail.ecu.eduwww.telemed.med.ecu.edu