President Bush's one thousand percent increase for first response technology and services in next year's budget is good news throughout the U.S., particularly in Atlanta where researchers at Georgia Tech's Center for Emergency Response Technology, Instruction, and Policy (CERTIP) are developing biomedical technology for detecting hazardous chemical and biological agents. Some of the $3.5 billion in the 2003 budget supports a new sensor and wireless communication devices developed on the Atlanta campus that work together as the primary lines of information gathering for accessing the nature and scope of a biological attack.
One of the primary things that first-responders need is a way of identifying biological hazards. Senior Research Scientist Daniel Campbell of Georgia Tech's Electro-Optics, Environmental, and Materials Laboratory will make that job easier. He is developing an "optic interferometic sensor" that identifies biological and chemical agents by measuring differences in speeds at which light travels through various biomedical media.
The portable sensor has three components: a laser light source, a planar waveguide, and a detector. The planar waveguide is a small piece of glass through which the laser light moves. The detector monitors light velocity changes provided by chemical reactions that take place on the surface of the waveguide. The waveguide's surface is treated with coatings that chemically respond to the specific biological agents, which is a direct method of detection.
The resulting chemical reaction changes the speed of light through the waveguide. The resulting velocity is compared to the velocity of a reference beam that is isolated from the sensing chemistry. Signal processing software then interprets the optic interferometic sensor's results and delivers chemical identification to a laptop computer in a few seconds.
The sensor measures many chemicals- including biochemicals and bio-organisms-all on the same substrate at the same time. It can be made to respond to many biological agents in the air and water. Future versions of the sensor will be linked to a smaller personal digital assistant (PDA) like the one described next.
PDAs give assessments PDQ
When aiding victims of biological attacks, first responders must usually administer treatment as soon as possible. A new software program developed by Georgia Tech Research Scientist Christina Baxter works through a PDA and dramatically speeds the treatment process. Using the benefits of wireless communication with a PDA also helped the team achieve one of their primary design goals, which was the replacement of an awkward system of cards and manual scoring for biohazard identification that is presently in use.
The software program Decision Aid reinforces the proper identification of specific biological agents by comparing the victim's symptoms and data from the optic interferometic sensor. Decision Aid poses questions to EMTs about a patient's skin sensitivity, blisters, and other symptoms. Responses to the questions are automatically scored against database information on chemical and biological agents.
The device provides the three most likely classes of agents along with the scores. Each of these agent classes is hyperlinked to a set of instructions (locally stored on the PDA) about procedures such as triage and decontamination steps the responder should take to avoid exposure. Data is also uploaded to a central command post for further analysis. The information is usually sent to a laptop computer that's also a web server, but it could be uploaded to any computer.
Decision Aid is especially important to responders wearing "full-level A" protective suits that severely limit their ability to conduct manual exams of victims, according to Baxter. Decision Aid works with another wireless technology developed at Georgia Tech called Medical ReachBack. Together, they may become the first lines of information gathering that experts could use for accessing the nature and scope of a biological attack.
Wireless network transmits info fast
Once EMTs know what they are dealing with, they need permission from doctors before administering antidotes. The Medical ReachBack system uses a secure wireless local area network to transmit vital patient information from first responders at the scene of a biological attack via the Internet to the central command post. The system transmits patients' vital signs to a local web server. Hospitals are connected through a wireless LAN link so doctors in emergency rooms can remotely assess patients' conditions and, if need be, order treatment by the EMTs on the scene.
This top view shows the workings of a single interferometer of the optical sensor developed by Georgia Tech researchers. A grating couples a broad beam of light into the waveguide. Half of the beam travels under the chemistry. The other half provides the reference and is shielded from any changes at the surface. Optical element-beam-splitters and internal reflection mirrors combine the beams for producing the interferometric signal. Assembling two or more interferometers on a single waveguide enables sensing of multiple biological and chemical agents.
The Medical ReachBack device consists of a laptop computer and medical instrumentation housed in a portable suitcase. "The case is small enough to carry into hazardous areas," says Mike Witten, a Georgia Tech research engineer working on the project. The device's medical instrumentation includes an EKG, non-invasive blood pressure monitor, and pulse oximeter.
All instruments are connected to the computer via serial cables. The medical parameters are relayed over a wireless LAN to the incident command post. "We incorporated a wireless LAN bridge and access point in a case with battery power and a web camera for providing situational information as well as a data relay point," says Witten. "The bridge case is on wheels and is easily pulled by first responders, even when they are wearing HazMat suits."
Most of the devices have their own batteries. The batteries on the computer used in the medical case are "hot swappable." They run about 1.5 hr each with the backlit display and about 3 hr each with the sunlight display. "We have four batteries in the case, so these can be swapped as needed," explains Witten.
Witten says that the computer processes the data, displays it locally, and then pushes the data to a patient information web site via the LAN. For data collection, the first responder requires no interaction once the system is running. The web-based system uses an Internet browser for accessing a secure web page to get information on an incident. Doctors using the Medical ReachBack system require no special software. The system uses a private network that requires user authentication.
During tests conducted by the CERTIP, EMTs, police, fire fighters, and military personnel relayed patients' vital signs to doctors at Grady Hospital in Atlanta and to the Edgewood Chemical Biological Center in Maryland. The information transfer allowed the doctors to diagnose the test victims and immediately prescribe antidotes.
Researchers at Georgia Tech are developing an integrated optic sensor that detects biological agents. It has three components: a laser light source, a planar waveguide, and a detector. Thin-film chemcial coatings on the surface of the waveguide change the speed of light passing through the waveguide when they contact different biological and chemical agents. The velocity is compared against that of a reference beam and can be correlated with the presence of chemical and biological agents. The sensor's signal processor and diode layer are beneathe the chemically selective coatings.
Local wireless instrumentation interconnection and testing of the Medical ReachBack through cellular-data and other low-bandwidth links are next steps, according to Witten. "Mostly, we will be improving the form factor and adding better forward communications," he says. "We will add 'forward' data messaging to the system to allow treatment instructions and permissions to go forward to the first responders." In coming years, re-searchers hope to reduce the size of the suitcase and to develop a wireless emergency EEG device.
Getting the big picture
Once the Medical ReachBack system provides feedback on victims, another Georgia Tech innovation tracks the locations of people in the field. The Situation Awareness Geographical Information System (SAGIS) creates electronic maps that superimpose various types of information in layers over a common map.
The SAGIS system uses Medical Reachback's wireless communication link for transmitting geographical information to Decision Aid's palm-top display about biological plumes and how they may spread. Alerting first responders in the field about biological plumes and the direction in which they may move driven by the current weather conditions provides information that first-responders need for determining which escape routes to use.
At the World Trade Center attack, first responders operated on numerous radio frequencies. "This accounted for some of the problems associated with coordinating their efforts," says Tom Bevan, founder of CERTIP. "There should have been one." He adds that there was disorganization and inability to communicate. The new technology described here helps fill some of the gaps in first-response technology.