Stem-202 Group Project 3

Participants: Daniel Wojtkowiak, Jordan Record, Jeshua Jerusalem
Course: STEM Scholars’ Research Lab II, STEM-202-HN01
Assignment Title: Solar powered heated blanket for hypothermia

Assignment Details

Hypothermia occurs when the body’s core temperature drops below 36°C (96.8°F) which can cause harmful bodily effects and even death. Hypothermia is dangerous in remote and cold environments, especially for patients who have suffered severe trauma. Currently, passive rewarming methods are commonly utilized to manage hypothermia, such as placing the patient in a sleeping bag or other insulating layers. These are often combined with disposable active rewarming devices; however, these devices are single-use and only function for a limited period of time. The goal of our project is to create an active rewarming device that is reusable and can be operated for extended periods of time, such as multiple days, without external logistical support. Additionally, the device will need to be sufficiently compact and lightweight to be easily transported, potentially in a backpack. Our design is a heating pad that gradually increases temperature to keep the patient safe while slowly raising their body temperature. The heating pad is powered by a battery pack, charged with a solar panel. This allows the pad to be operated for extended periods of time, especially if multiple batteries and solar panels are carried so that as one battery dies, it can be replaced with a fully charged one. This way, the battery will not run out of charge and the heating pad will stay operational. A patient experiencing hypothermia requires a reliable and sustained heat source to return to an optimal body temperature, which our device will provide.

Application

Given our interest in emergency medical situations, our team identified the need for a medical device to manage hypothermia in austere environments. We researched the market and found that the majority of available solutions were disposable, and their maximum output time was no greater than ten hours. We found one rescue blanket for thermoregulation; however, for many users, the >$5000 price tag would be cost prohibitive. Thus, we set out to design a cost-effective renewable energy solution that could be used reliably for extended periods without depending on external power sources.

Our thermal pad is designed for emergency situations in which someone is experiencing hypothermia, such as exposure to extreme cold temperatures or in a state of shock. The major components include a 12” by 24” heating pad that is powered by a 120W portable solar panel with a rechargeable portable battery bank with A/C output. We have coupled our device with a foam mat to serve as the base, a mylar blanket, and a wool blanket to serve as additional insulation and protection from the elements. Excluding the cost of the mat and blankets, the components of our device cost less than $350.

Results/Conclusions

The graph above illustrates temperature changes over time for the highest and lowest settings of the blanket, serving as an estimate of the temperature range and the variance over time. These data would help to inform the user as to the capacity of the device as they monitor the impact of the blanket on the patient’s body temperature.  

Over the course of our project, we gained a deeper understanding of the significant danger that hypothermia can pose, especially in remote environments where treatment options are limited. We recognized the crucial role of active rewarming in preventing heart and respiratory failure. We explored how sustainable energy sources, such as solar power, can enhance the duration and reliability of medical devices. On the engineering front, we explored the complexities of designing a heating system that is not only effective but also portable, lightweight, and reusable, ensuring it can provide warmth for extended periods.

Challenges and Successes

Our team is composed of two mechanical engineering students and one biology major. Thus, we consulted with an electrical engineer and conducted online research to determine the appropriate specifications for our components.

Throughout the project, we were met with challenges related to our equipment. We researched, tested, and modified our design by adding or replacing various components to create a functional prototype. 

One clear challenge we faced was the impact of a cloudy day on the efficacy of our device. With less sunlight, the solar panel would likely be able to collect less energy than on a clear day. However, when testing the device under cloudy conditions with a UV index of 3, we confirmed that it harnessed sufficient power from the sun to function effectively.