STEM II, instructed by Dr. Crowthers, is a project-based course focused on the development of assistive technology to support individuals with disabilities within the local community. As part of the course, students form collaborative teams to identify real-world problems and design practical solutions. For this project, I worked alongside Sharvi Pujari, Lauren Kim, and Aarushi Khatri. This experience provided valuable insight into the engineering design cycle and its application in addressing community needs.
Problem Description
Individuals with Frontotemporal Dementia (FTD) often struggle with spatial awareness, judgment, and memory, which can lead to unsafe behaviors such as wandering or touching hazardous objects. This project aims to develop a wearable wristband system that provides context-aware audio prompts using familiar caregiver voices to help individuals with FTD navigate daily environments more safely and independently.
Approach
Our approach involves creating a two-part system: a stationary sensor unit using a Raspberry Pi 5 and a wearable wristband powered by an ESP32 microcontroller. When the wearer comes within a 1-meter range of the sensor—placed near a hazardous area or exit—the wristband triggers a pre-recorded, context-specific audio message in a familiar caregiver’s voice. This design provides timely, personalized prompts to guide behavior and enhance safety without restricting the user’s mobility or autonomy.
Prototype 1
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Final Product
The FTD Safety Wristband is a wearable assistive technology designed to improve home safety and autonomy for individuals with Frontotemporal Dementia (FTD). The system consists of two primary components that work in tandem using Bluetooth Low Energy (BLE) proximity sensing: a stationary Raspberry Pi 5 and a wearable ESP32-based wristband with an onboard speaker. The Raspberry Pi 5 is strategically placed near areas of concern—such as kitchens, staircases, or exits—and continuously emits a BLE signal. The wristband, worn by the user, contains an ESP32 microcontroller that scans for this signal and calculates its Received Signal Strength Indicator (RSSI). When the RSSI exceeds a preset threshold (e.g., -70 dBm), indicating that the user is within ~1 meter of the hazard zone, the ESP32 triggers a real-time tonal audio alert through an embedded speaker. This alert serves as a gentle, non-invasive reminder to pause or seek caregiver guidance before proceeding further. The wristband operates entirely without the need for internet or smartphone access, making it ideal for elderly users and caregivers seeking a low-maintenance, standalone solution. Its 3D-printed enclosure houses the ESP32, a 3.7V rechargeable lithium battery, a Uxcell mini speaker, and an IRF520 MOSFET driver module to control power delivery. The modular design allows for easy battery replacement, while the audio alerts can be customized with caregiver-recorded messages uploaded via a USB connection. The current prototype has been tested to detect BLE signal strength reliably up to 10 meters, with optimal alert triggering at distances of 0.8 to 1.0 meters. This early-warning system helps prevent users from unknowingly entering dangerous zones, providing an added layer of safety while supporting their independence within the home.
Links
If you would like to view an instruction guide on how to use this device, click on this link.