Dreaming Up an Interactive Ambulance

     When it comes to wirelessly linking the back of the ambulance to the emergency department, telemetry hasn't traditionally been the problem-streaming real-time patient vitals doesn't require that much bandwidth. It's the video required for actual telemedicine that really gobbles it up. Consequently, many EMS telemedicine efforts have required the infrastructure to support high-bandwidth applications. But for a recent project in Texas, they tried a different approach.

     "Our effort," says James Wall, PhD, director of the Computing and Information Technology Division of the Texas Center for Applied Technology at Texas A&M University, "centered on how to aggregate multiple low-bandwidth systems to get a virtual pipeline big enough to support video."

     The results are on the road now in a pair of Texas jurisdictions.

     The project emerged from a partnership between the A&M system and the University of Texas Health Science Center in Houston. Their collaboration, called DREAMS (Disaster Relief and Emergency Medical Services), involved work on digital technology that could better connect medics in the field with docs in the ED.

     "Basically the idea was trying to overcome the negative impacts of time and distance on EMS transports," says Wall, who was co-principal investigator for the project's latter component. "So right away we focused on rural areas, because that's where this problem is. And in order to offset the time and distance problem, we thought if we could get a physician involved sooner, we'd have better outcomes with respect to morbidity and even saving lives."

     Doing that required video, and so to that end, project architects developed what they call an Intelligent Communications Manager. This enables multiple low-bandwidth communications systems-things like cell phones, satellite phones and data radios-to be combined to produce enough bandwidth to send things like video.

     The system can employ whatever combination of any or all of these is available. The intelligence comes into play when, for instance, a cellular signal is dropped. If the available bandwidth shrinks while an ambulance passes through a dead spot, data is prioritized so the most important continues to get through. Frame rate and resolution are automatically adjusted in response to how much bandwidth the system finds available.

     Ambulances with this capability, known as Interact ambulances, also feature digital video cameras, 12-lead EKGs, vital signs monitors, ultrasound, blood analyzers, GPS navigation, ruggedized laptops and bar-code scanners, all of which can be hooked in to contribute data. The video stream is only one-way, but a physician in the ED can remotely control the cameras to pan, tilt and zoom for better views of the patient. There are currently five Interact ambulances in use: four in Liberty County, outside Houston, and one at St. Joseph Regional Health Center in Bryan.

     Interestingly, they've relied primarily on cell phones in their operations to date.

     "When we started, I think we expected much more heterogeneity in the systems we were using," says Wall. "But the reality is that cell phones have gotten so good, we've just been aggregating those."

     The DREAMS project ended a year ago, but a subsequent project involving many of the same players, T5 (for Texas Training and Technology for Trauma and Terrorism), is now focused on migrating the technology to the air-medical environment.
-John Erich, Associate Editor