Slashing response time
The Mecklenburg ESMA in Charlotte, NC, improves its ability to respond to 9-1-1 calls.
If you are a citizen and you dial 9-1-1, you expect help immediately. But suppose you are the one responsible for providing that help, and you simply don’t have the resources to respond in a timely fashion. The Mecklenburg Emergency Medical Services Agency (ESMA), based in Charlotte, NC, faced that problem. ESMA serves both that city and Mecklenburg County, comprising 542 square miles.
So, in November 1996, a consulting firm, Fitch & Associates, Platt City, MS, was hired to work with county and medical officials to improve the situation. The company determined that, based on national standards, the response to all emergency calls should be less thantwo minutes from the time the public safety answering point (PSAP) received the call until a unit is dispatched. Various improvements were implemented, including retraining staff, hiring more paramedics and putting more emergency vehicles on the road.
But a key ingredient to the turnaround was upgrading the communications system. American TriTech, San Diego, was the system integrator hired to redesign, upgrade and implement the system. Chris Maloney, president of American TriTech, said that the two main tasks were to incorporate a new computer-aided dispatch (CAD) system to replace the outmoded one installed in 1993 (designed primarily for nonemergency convalescent transportation), and to merge fire dispatch with ambulance dispatch, the two systems both having previously been separate.
A clear priority, said Barry Bagwell, communications systems manager for Mecklenburg ESMA, was a records management system that allowed high-performance, real-time decisions on how best to use and move the response vehicles. To this end, Global Positioning System (GPS) technology was added, supplied by Trimble Navigation, Sunnyvale, CA. The radio system was upgraded to Motorola’s CRT Gold Series, with the previous 9-1-1 PSAP equipment being replaced by Positron, Montreal, and digital logging equipment provided by Seltronics Eyretel, Landover, MD, with console furniture from Watson Furniture Systems in Bainbridge Island, WA.
“What we wanted to do was reduce response time, while also expanding service into the fire area, so we felt we had to have a better picture of where the vehicles were at all times, hence the addition of our automatic vehicle location (AVL) system. We needed a CAD system to accommodate that position information and to display it on a high-resolution map in the dispatch center,” Maloney said. The ESMA ambulance fleet consisted of about 35 vehicles, 18 to 25 of which were on duty at any one time, along with the assorted vehicles from 17 volunteer fire departments. Also to be accommodated were about 55,000 calls to 9-1-1 received annually.
In the old system, dispatchers and PSAP call takers used a single phone line. Under the current system, every dispatcher and call taker has two monitors linked to one Windows-environment PC in every position. One monitor displays traditional CAD information such as incoming requests for service and vehicle status. The other monitor depicts a detailed map showing the location of the vehicles in the county. The system includes a number of tools that help dispatchers reduce response time.
Vehicles are not assigned to particular areas. Rather, they are kept in a fluid state so that the system can analyze data, predict where the next response might occur and then make the best use of that vehicle. “It’s a bit like a zone defense in basketball,” Maloney said. “If one player breaks for the basket, then the others arrange themselves to best cover the court.”
Historical data are analyzed by the system in two ways. The first is by the time of day and day of the week, through which the system adjusts to an expected call volume and provides for the appropriate staffing levels.
The system adjusts the staffing level to ensure an optimal number of units are on the road at the peak periods. “At Denny’s you’ll find more wait staff on duty at 10 a.m. Sunday morning than at 2 a.m.,” Maloney said. “It’s a basic concept, but for some reason it’s not utilized a lot in public safety.”
The second mode of analysis is spatial. “The system looks at historical demand patterns, then shows the user where to place those vehicles, depending on what is available at which point of time, and then does it for every hour of the day for every day of the week. In other words, there are 168 plans,” Maloney said.
The system then calculates what happens when vehicles are in use. For instance, if 10 vehicles are on duty for 8 a.m., Monday, what happens if one, two, three or more are responding to different incidents? Where do the remaining ones go?
The AVL system determines where all of the vehicles are at all times. GPS polls the vehicle rapidly, every five to 10 seconds, following the route, with the ability to provide directions if the driver gets lost. But if the vehicle is in a non-urgent status, whether parked at the station or offloading a patient, the polling diminishes.
The AVL system provides a map on the screen showing where the units are so that if there is a 9-1-1 call, the closest unit can respond. The system automatically chooses this unit, but the dispatcher can override this choice if, for some reason, another vehicle is more appropriate.
In some situations, however, the vehicle might move from its last location without notifying the dispatcher. “If the dispatcher assigns a vehicle on the basis of its last location, but it is actually five to 10 miles down the road, the result might be a serious error and poor response time,” Maloney said.
For this eventuality, the AVL system incorporates a mobile status terminal. The driver keys in seven main status reports, such as the unit “has started toward the scene,” “has arrived,” “is leaving with the patient,” or “has arrived at the hospital.”
The CAD system picks up these status changes and updates the displays on the system. By automating the status changes, about 80% of the dispatcher’s work load is eliminated, freeing him to do more important things such as managing the vehicle routes,” Maloney said. By automating these status changes into short, standardized messages, radio time is considerably cut back, thus helping the agency to manage spectrum efficiency.
“Unit utilization is really a measure of productivity,” Bagwell said. “Our ultimate goal is to minimize response time and to do that with the fewest number of vehicles or unit hours.” Bagwell said the system also allowed the agency to produce and to maintain its own maps. The agency works closely with the county, which identifies changes, such as a street condemnations or name changes. It downloads that information every Sunday so that the maps that then go up on the 9-1-1 response screens are always current.
The next system became operational in September 1997. Bagwell reports that the agency, in a year’s time, has moved from 77% to 86% compliant. Much of that was due to the other factors such as hiring more paramedics and purchasing more vehicles. With the new communications system in place, Bagwell anticipates the agency will meet the required 90% compliance standard.
“It’s one thing to reach the 90% compliance stage, but the real test is maintaining it with consistency, with real time monitoring. But that’s what this new system will enable us to do,” Bagwell said.
The basis of proper public safety is communications. Firefighters, police and emergency medical services usually answer calls when they are coming to someone’s rescue, or they are dispatched to the scene of danger. What lies behind proper public safety, therefore, is proper communications equipment.
Patriot Ambulance in Lowell, MA, and the Verdugo Communications Center, in Southern California, have chosen Vega consoles to aid in the protection of the public.
Patriot Ambulance installed Vega’s 10-line and four-frequency, tone format control console, model C-5110B. The console is operational at one of its three dispatch stations, and the company is planning additional Vega systems to strengthen communications among 250 employees and 40 service vehicles.
The C-5110B provides simplex operation over two-wire or four-wire lines and duplex operation over four-wire lines. Additionally, dispatchers can monitor (through a second speaker) any combination of those 10 lines that are not already selected for transmit and receive control.
The Verdugo Communications Center, a central dispatch facility, services five fire departments in Southern California using two Vega C-5112 10-line and multiple-frequency modular consoles as backup communications equipment to its main on-line Motorola system.
In case of equipment failure, the center immediately switches to its two Vega emergency system consoles for dispatching communications to fire departments in other cities. The consoles were purchased one year ago to support the system.
The compact C-5112 unit provides instant PTT and timed mute features among many other features. The console includes two speakers and volume controls to independently adjust selected-line and unselected-line audio levels. Individual volume controls are provided for each “unselected receive” line.
Any line or combination of lines can be selected for transmit and receive operation. The 10 “unselected receive” switches allow any combination of lines to be monitored through the “unselected” speaker.