Prehospital Applications of
Telemedicine
Debra Perina. MD
I. Historical Perspective
Telemedicine began as a concept in the 1970s. With the advent of high speed data transmission lines, such as T1 lines in the early 1980s, this became a reality.
Governmental initiatives and grant funding allowed for the development of an infrastructure connecting medical sites with real-time audiovisual connections that allowed for patients to receive care in consultation from remote caregivers.
Real-time transmission
High quality resolution
Two way communication interface
Secure transmission network
Patient consultations from tertiary care centers
Physician connection to rural mid-level provider clinics
Educational opportunities
Direction of procedures
Feasible only recently when real-time video transmission became possible through wireless connections via microwave or satellite up-link transmissions.
Real-time transmission
High quality resolution
Two way communication interface
Secure transmission network (analog vs digital)
·
Portable
equipment
·
Wireless
transmission
Prehospital pilot projects using telemedicine concepts include:
A. Ground Based
1. University of Texas, Houston, Dreams project -
This project is utilizing real-time audio and video to connect
Houston EMS with the University of Texas receiving hospital.
2. University of Maryland, Brain Attack project
This project is using real-time telemedicine video feed through
microwave transmissions to connect ground EMS agencies in
Baltimore City and the University of Maryland receiving hospital.
This technology is only being employed in cases of suspected
stroke patients to allow the neurologists to complete a neurological
examination on the patient prior to arrival to the hospital, in order to
shorten the interval between onset of systems and use of
thrombolytic drugs.
3. CISCO Project, Southwest Research, Tucson, Arizona
This project is to connect ground EMS with receiving hospitals in a
real-time video connection. This is projected to include aircraft
linkages.
4. San Antonio project,
This project connects ground EMS units with San Antonio receiving hospitals.
5. New York State EMS Authority,
This project allows photos taken at the incident scene to be
transmitted to the receiving hospital. These photos will be used by
medical personnel to aid in determining the potential extent of a
patients injuries based on the mechanism. This project uses static
displays and no video or audio transmissions.
6. Arizona ER Link Project,
This Project connects prehospital providers with the receiving hospital ground based units by two-way video, voice, and visual datalinks. This is in the beginning stages and eventually is projected to include air transport as well.
Problems encountered include:
Line-of-sight transmission resulting in poor penetration
Poor video quality
Signal distortion
B. Aeromedical:
To date all identified projects have been military.
1. U.S.
Coast Guard
Goals included to be able to provide surveillance of other craft
remotely by officers on land through a video stream from a Coast
Guard vessel, and the ability to offer instructions to Coast Guard
personnel to provide medical care to patients encountered on the
high seas.
2. U.S.
Navy (in conjunction with the Uniformed University Casualty
Research Center),
Goals related to enhancing the survival of battlefield casualties by
connecting physicians with field medics through video linkages,
allowing for remote assessments and instructions to field medics.
This potentially could expand practice capabilities of medics.
Problems encountered include:
Analog signal
Poor transmission quality
Delay in video feed
A. Concept: Real-time video connections between ground EMS
providers and air medical crews enroute to the scene will facilitate
patient care.
B. Benefits:
Shorter time to critical care
Better air crew pre-arrival preparation
Shorten scene times
Enhanced safety margin for helicopter operations
Faster return to normal operations
C. Project Parts:
Phase 1: Feasibility - Identifying similar projects, sources of
problems, and equipment options
Demonstration Best identified equipment publicly
demonstrated as effective and workable
Phase 2: Implementation Phase Equipment identified, procured,
and implemented. Data collection in progress.
D. Project Equipment:
Connection between ground EMS crews and aeromedical service:
Helmet mounted video camera
One-way video ground to air
Two way audio
·
Highly
Compact Encrypted Digital transmission system with data rates up to 25 Mbit/sec
VIDEO - MPEG II (DVD quality) video encoding
AUDIO - Dual (CD quality) audio
channels
DATA - High speed auxiliary data channel
·
Robust
forward error correction - multi-path
immunity
·
Scaleable
bandwidth - allows efficient frequency utilization
Transmitter:
·
Rugged
environment design
·
shock,
vibration, temperature resistant
·
Power
15 watts
·
Integrated
MPEG II encoder
·
Wide
frequency tuning range
·
1.9 to
2.7 GHz
·
PAL or
NTSC
·
PC/PDA
remote configurable interface
·
0.5
watts RF output power
·
Accepts
multiple video input sources
Receiver:
·
Rugged
aluminum construction
·
Built
in LCD screen
·
12VDC
operation
·
Light
weight, portable
·
Auxiliary
video and audio outputs
·
On
screen system status
·
Signal
level, SNR and BER
·
User
defined graphic/character overlays
·
Self
contained or external antenna options
·
1.9 to
2.7 Ghz operator selected preset channels
Law Enforcement
Military
Fire Service
Transportation Departments
Community and State Health Departments