In the medical realm, offering treatment to a patient who has suffered serious trauma within the first 60 minutes of injury greatly boosts the chance of survival.
This “golden hour” also exists on the battlefield, where advancements in medical techniques have helped to preserve the lives of thousands of troops when precious minutes can demarcate the difference between life and death.
But to gain a lead on the fragile hourglass of medical intervention for war-related ailments and injuries, militaries have been searching for technologies that can remotely monitor the welfare of an individual on the battleground and alert unit commanders and medical personnel of problems.
Until recently, such devices were prohibitively bulky and expensive, consumed power rapidly and had meager transmission capabilities.
But with the advent of personal handheld electronics and the miniaturization of components, the ability to package such sensors inside palm-sized devices has allowed remote welfare monitoring systems to become feasible in war zones.
Hidalgo, Ltd. based in Cambridgeshire, England, has developed a small sensor that monitors a person’s cardio-respiratory welfare and temperature, among other vital signs. The device also gauges how a person is positioned, whether standing or supine. Algorithms then calculate the person’s well-being using the data, says Justin Pisani, technical director.
“That’s quite powerful, being able to remotely know whether the 10 men you have lined up are actually moving, and to a degree, what sort of activity they’re engaged in,” he says.
Worn on the sternum, the device, called Equivital, contains a low-power mobile computer, amplified circuits and accelerometers. It has a number of electrical interfaces that connect through a sensor to the body.
“Basically you’re wearing a belt that has some intelligent areas woven into it, where it can sense parts of the body, and it can pass small electrical currents off the body through into the sensor,” says Pisani. The computer turns those electrical currents into digital data, and using some miniature accelerometer techniques originally developed for measuring movement in robots, the sensor can determine whether someone just stood up, or is lying down.
It sends out a “traffic-light” output that can be displayed as icons on a digital map, much as friendly or enemy forces are represented on blue force tracking systems. An icon that is green means an individual is well. Amber represents an individual with abnormal levels and red requires immediate attention.
To see more details on an individual, clicking the icon calls up a secondary screen with physiological readings and movement information.
“It’s got all these wave forms that would look quite at home in a normal clinic,” Pisani says. The program’s color code system can be calibrated to indicate other problems, including heat stroke symptoms.
The sensor itself is designed to communicate within a local area, between 10 and 100 meters, depending on the transmission technology and environment. Transmitting further requires a connection into other communications devices, such as a cell phone or a radio.
The company is embedding its system into military tactical communications gear, such as handheld radios. “We can overlay our data on that communications system,” says Pisani.
Traditional hospital bedside monitoring systems send patients’ physiological data to a remote collection point, often at the nurses’ station. On the battlefield, that model presents a problem. “That means you have to send a lot of data between the soldier and the remote point, which is clearly not viable if you’ve got lots of soldiers and radio links that don’t have masses of bandwidth,” says Pisani.
That in part is why the company has developed the traffic light output, to minimize the amount of data being sent out over the network. But in the event of a casualty, the sensor can be switched to deliver more data automatically to help a medic administer appropriate care to the wounded.
“That’s important because you don’t want them wearing a kit that tells you only a little bit about the injury and have to take it all off and put on another kit to monitor them,” says Pisani.
Because it uses commercially available technologies, the device runs about $500, says Pisani. “It’s no good if it’s such an exotic technology that you can only justify putting it on a few people.”
The current technology will be deployed soon with Western special forces and Army Stryker units for trials in a number of environments, including the Middle East.
“We hope that will be a good step forward,” says Pisani.
The company is working on reducing the size of the device by 50 percent. Its ultimate goal is to incorporate the sensor into a uniform as intelligent fabric technologies are developed and improved.
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