Sensors That Can Save First Responders

Fighting Fire with Technology: Vital Sign and Environmental Monitoring for First Responders on the Front Lines

Image Source: wittayayut/Stock.adobe.com; generated with AI

By Alex Pluemer for Mouser Electronics

Published December 22, 2023

First responders perform essential services in situations that potentially threaten their lives and the lives of those they help. Firefighters are frequently exposed to extreme heat, smoke inhalation, and airborne particulate matter. EMTs can be exposed to dangerous narcotics or toxic chemicals that can be absorbed through the skin or via respiration, sometimes without their knowledge (until symptoms begin to occur). Firefighters and paramedics are often asked to enter unstable structures and towers in the case of building collapses or house or apartment fires. The wide range of situations first responders encounter and the quick thinking and improvisation their jobs require ensure that they won't be replaced by intelligent robots anytime soon, but technology can still make saving lives safer and more efficient.

Vital sign monitors—including heart rate, blood pressure, and blood oxygenation sensors—can let first responders and their supervisors know when they need medical attention. In the case of a building or structural collapse, body movement and positioning sensors can let supervisors know when first responders may have fallen or been knocked unconscious.

Environmental sensors can measure local temperature and humidity and the presence of airborne pollutants like toxic gases, volatile organic compounds, and particulate matter, exposure to which could have severe short- and long-term health effects. Analyzing all the data that sensors collect at the edge can help optimize future emergency response plans and better prepare emergency personnel for specific challenges and scenarios in the field. In this article, we'll look at some ways technology can make emergency response safer and more effective.

Vital Sign Monitoring

Portable heart and blood pressure monitors aren't new technology; doctors prescribe them daily to monitor patients' health outside of clinical settings. They're also widely available features in many commercially available smartwatches and fitness trackers. They typically relay data from a device on the user's body to a central processing hub (and to an app on a smartphone) that monitors vital signs for any abnormal activity that may indicate the user is in some kind of medical distress. Vital sign sensors designed for emergency response personnel function similarly but must be built to withstand much harsher potential conditions. First responders are asked to work under extreme heat, standing water, and possible exposure to toxic chemicals or substances, and their equipment must be able to withstand those same conditions.

Health monitoring isn't limited to just heart rate and blood pressure. For first responders and firefighters, in particular, monitoring body temperature and blood oxygen levels is also vitally important. Firefighters on the front lines are susceptible to heat stroke and other conditions related to heat exposure; monitoring body temperature can tell first responders and their supervisors when they need to cool down. Smoke inhalation is another on-the-job danger of firefighting, and the adverse effects of smoke inhalation often aren't noticed or detected until several hours or even days after exposure. Pulse oximeters measure the oxygen levels in the blood by shining a light through the skin into a blood vessel; the amount of light the blood absorbs indicates how oxygenated it is. Low blood oxygen levels can indicate dangerously high levels of carbon dioxide in the bloodstream because of smoke inhalation, so an oximeter-based warning system for possible smoke inhalation can save lives.

Body positioning sensors, like the type of sensors fitness trackers use to count your steps, can also tell supervisors when first responders are lying prone or in an unnatural position. This is particularly helpful in building or structural collapses that create falling debris: Knowing when first responders have been knocked down can save their lives and the lives of those being rescued.

Environmental Monitoring

Measuring ambient temperature and humidity and monitoring air quality for gases, toxins, or particulate matter is common practice in industrial and manufacturing settings. Certain vehicles that transport heat-sensitive materials, especially potentially hazardous materials, may also implement environmental sensors to ensure their cargo reaches its destination safely. The challenge in designing environmental sensors for first responders is making them as lightweight and unobtrusive as possible while maintaining durability in harsh conditions.

Local temperature and humidity sensors are relatively basic, but monitoring air quality in a mobile implementation is more complicated. Typically, stationary devices detect gases and particulate matter in the air through light refraction, in which the device emits a laser that gets reflected toward a diode on the device (Figure 1).

Figure 1: Portable gas detector device for testing the gas condition before entry to refinery plant. (Source: Nattawit/Stock.Adobe.com)

The intensity and quality of the light the diode receives compared to the laser "illuminates" what's present in the air. Certain gases reflect light differently than others, and larger pieces of particulate matter reflect more light than smaller ones. Light-emitting and light-receiving mechanisms can be delicate; tailoring them for harsh environments requires specific materials and structures to protect them from extreme heat and falling debris.

Real-Time Data Analysis

Analyzing data from different sources (i.e., individual first responders carrying their own environmental sensors and vital sign monitoring apparatus) can help supervisors coordinate emergency response plans to optimize safety and efficiency. Information coming directly from the front lines of an emergency often changes before supervisors in the field receive it (Figure 2).

Figure 2: Firefighters assess real-time conditions to determine course of action for extinguishing fire. (Source: Gorodenkoff/Stock.Adobe.com)

In a multi-room or multi-floor building fire scenario, the difference between the ambient temperature in disparate parts of the building can help tell firefighters where the fire is burning at its hottest, helping them plan an evacuation route that avoids those locations. In situations where dangerous toxins or other pollutants are present in the local atmosphere, like a chemical spill or industrial accident, first responders on the scene can use air-quality monitoring technology to tell them where the highest concentrations are located. This can also help them determine victims' possible exposure, potentially accelerating treatment before symptoms even begin to appear. If a first responder on the scene becomes unresponsive or otherwise unable to communicate, body positioning sensors can immediately tell supervisors if they may be in danger or in need of medical attention.

Data collected and analyzed from the scene of disasters and other emergency responses can also help supervisors plan for future response scenarios. Monitoring the vital signs of first responders at forest fires can help determine the optimal length of a single shift exposed to extreme heat and poor air quality, optimizing firefighting and rescue operations and preserving the long-term health and wellness of firefighters. Data on the short- and long-term effects of exposure to high levels of toxins or particulate matter in the air can spur the development of more effective means of protection against similar pollutants.

Conclusion

First responders must leap before they look; emergencies happen fast, and there isn't always time to collect information and assess risk before acting. The more real-time environmental data available to first responders and supervisors, the more safely and effectively they can perform their jobs. Environmental monitoring can help keep first responders safe and aid in developing treatment plans for victims exposed to toxic materials. Monitoring the vital signs of first responders can keep them healthy and working effectively. It can also provide data that help medical professionals determine the long-term effects of work-related hazards such as smoke inhalation and develop better protective systems and treatment options for first responders.

Completely automating emergency response on the front lines isn't feasible yet, as most emergency response scenarios require too much improvisation and quick thinking to hand over to machines anytime soon. If we can't use technology to take people out of harm's way altogether, we can at least use it to make the people who help us in times of crisis as safe as possible. With mobile monitoring technology for vital signs and the environment, we can do just that.