STEM II is taught by Dr. Crowthers. In this course students work in groups of typically 3-4 students to create an assistive piece of technology that serves a need in the community. I worked with Venkatraman Varatharajan, Shuling Lin, and Emily Wang to create a device called TrustFall, which aids fall risk patients by detecting when they are falling and inflating an airbag to cushion them.

Problem Statement

Adults over the age of 65 have a great risk of falling, especially on the hip. Devices exist to prevent a fall, but there are very few devices designed to protect an individual during a fall.

Therefore, the goal of the project was to design a device that could protect a fall-risk patient in the event of a fall.


As humans age, they are more prone to falling. Every year, 35% of older adults over the age of 65 and 45% of adults over the age of 70 experience a significant fall. As an individual ages, they are prone to develop fall risk factors such as osteoporosis, decreased cognitive ability, and issues with balance and walking (WebMD Editorial Contributors, n.d.). Hip injuries for older adults are not only harmful in the short term, but a single hip injury can acutely impact an individual's quality of life. As an individual ages, the recovery time for someone who has experienced a traumatic fall also increases (C. Cerqueira, personal communication, March 10th, 2023). When older adults first start showing that they are at risk of falling, in order to maintain their independence, they may be recommended to use a walking cane. If the chance of falling worsens, a possible next step could be the use of a walker (C. Cerqueira, personal communication, March 10th, 2023). Even with numerous preventative measures, older citizens are still at risk of falling while going about their day-to-day life. Uneven terrain poses a challenge to individuals using a walker, as navigating it may lead to a loss of balance resulting in a fall. Falls are a serious health concern for the elderly; in fact, over 95% of hip fractures are caused by falling. This is concerning for older adults as hip fractures result in 300,000 hospitalizations annually (CDC, 2020).

In order to lower their risk of injury during a fall, our team created a product that can help all older adults, with a focus on fall-risk patients. Our device - TrustFall - is designed to cushion older adults in the event of a fall. If the user is falling, a sensor (such as an accelerometer or gyroscope) will register the fall, activating an airbag-like device to cushion the individual before they contact the ground. This device is designed for all elderly individuals who have a risk of falling or might become fall-risk in the future. In order to build our device, we needed guidance from both older adults and the doctors and nurses that work with them. These older adults have trouble walking and need a device that will help protect them while not causing their risk of falling to increase - for example, adding too much weight for them to carry. Our device is not meant to assist in their movement; rather, it is designed to protect the user in case of a fall.


We started off with 3 designs. The first was the AirBackpack, which contained three airbags positioned around each hip and the back of the user. We felt that the design was not effective in that the wrong airbag might accidentally deploy, and it was not safe for the user. The second design we considered was a mono airbag belt, which consisted of a singular airbag wrapped around the user's waist. This design also proved to be ineffective because upon inflation, the airbag would not inflate evenly. We eventually settled on a design containing two airbags (one for each hip) and the circuitry placed in between. The following is a visual of the designs:


After conducting several design studies on the final prototype (namely, airbag quality, fall detection accuracy, and valve activation), we were able to conclude that the three main parts of our device were all.

When the bag was in the closed position, the tubing and valve were not able to withstand the pressure of an open CO2 canister and they detached from each other. This caused an issue for us as our original activation method involved having the CO2 canister open at all times and then opening and closing the valve. At this point we realized our plan would not work and we realized that we would not have enough time to work with a different valve or to create a different mechanism for allowing the CO2 to enter the airbag.