LifeLink — Smart Health-Safety Bracelet for Elderly Safety

News

Proud Finalists of the 10th Galaksija Cup

The LifeLink project has been selected among the best projects and will participate in the finals of the prestigious high school competition in electronics, telecommunications, and automation - 10th Galaksija Cup.

This success validates our dedication to developing innovative solutions for the health and safety of the most vulnerable, giving us an immense motivation to continue refining our smart bracelet.

Learn more about the project

Features

Everything needed for safety

A complete system for tracking health and safety of the most vulnerable patients and elderly people, designed with attention to every detail.

Advanced Fall Detection

3-phase algorithm uses QMI8658 IMU (accelerometer + gyroscope) to detect free fall, impact, and immobility. Orientation check eliminates false alarms.

1 Free Fall
< 0.6g

→

2 Impact
> 3.5g

→

3 Immobility
5 seconds

Vital Signs Tracking

MAX30102 sensor measures heart rate (BPM) and oxygen saturation (SpO2) in real time using FFT signal analysis.

Automatic SMS Alert

SIM800L GSM module sends an emergency SMS with GPS coordinates (Google Maps link), heart rate, and fall status to a contact person.

Interactive UI (LVGL)

Dynamic interface with gesture navigation, status bar, numpad for number input, and debug sensor display on a 466×466 AMOLED screen.

Countdown & Cancellation

A 5-second countdown screen allows the user to cancel a false alarm by tapping the screen before the SMS is sent.

BLE Connection

Bluetooth Low Energy SPP server for future communication with a mobile application and device diagnostics.

Always protected

Mission

Technology serving loved ones

Falling is one of the leading causes of injury among elderly people and the most vulnerable patients. LifeLink is designed with a single goal — to provide security and swift response exactly when needed, even when the person cannot call for help themselves.

37.3M

Falls per year requiring medical attention globally

<10s

Time from fall to sending SMS alert with GPS location

24/7

Continuous monitoring of vitals and fall detection

No smartphone required

Automatic SMS with Google Maps location

Option to cancel false alarms

Technology

Engineered on ESP32-S3 platform

LifeLink uses the ESP-IDF framework as its foundation, alongside the LVGL graphics library for a premium user experience.

Download ESP32 Firmware GitHub Project

ESP-IDF v5.4

Official Espressif development framework providing full hardware control. Multi-tasking based on FreeRTOS.

LVGL Graphics

A lightweight and powerful library for embedded devices with animations, gestures, and custom themes.

ESP-DSP Hardware Acceleration

Hardware-accelerated FFT signal processing for real-time PPG analysis with 100Hz sampling rate.

AT Commands GSM

Communication with the SIM800L GSM module via UART for network registration, SMS dispatch, and status checks.

Algorithms

The science behind detection

Sophisticated signal processing algorithms ensure accuracy and reliability in critical situations.

FFT Analysis of HR & SpO2

Fast Fourier Transform (FFT) analyzes the PPG signal from the MAX30102 sensor for robust heart rate and oxygen saturation estimation.

Sampling Rate 100 Hz

Buffer Size 512 samples

Detection Range 30–240 BPM

Window Hann Window

SpO₂ Formula: SpO₂ = 110 − 25 × (AC_red/DC_red) / (AC_ir/DC_ir)

3-Phase Fall Detection

A state machine-based algorithm utilizing Signal Vector Magnitude (SVM) to distinguish genuine falls from daily activities.

SVM (Total G-force): SVM = √(ax² + ay² + az²)

Orientation Check: θ = arccos(v_ref · v_curr / |v_ref| · |v_curr|)

Free-Fall Threshold < 0.6g

Impact Threshold > 3.5g

Immobility Confirmation 5 seconds

Orientation Change > 60°

Hardware

Carefully selected components

Every component is chosen specifically to ensure reliability, accuracy, and efficiency.

ESP32-S3

Dual-core Xtensa LX7 MCU with Wi-Fi and BLE 5.0 support

MCU

Round AMOLED

466×466 pixels, high contrast, and deep black for premium display

Display

SIM800L GSM

Compact Quad-band 2G module powered directly from a 3.7V battery, AT commands over UART

Cellular

QMI8658

6-axis IMU (Accelerometer + Gyroscope) for precise motion detection

IMU Sensor

MAX30102

Optical sensor for measuring heart rate (BPM) and oxygen saturation (SpO2)

Health

AXP2101

Advanced power management IC with multiple output voltages

PMIC

Interface

Intuitive user interface

Gesture-based navigation between screens optimized for elderly users.

Dashboard

Primary watch face displaying vital signs, time, and connection status icons (GPS, GSM, BLE, Battery).

Main Screen

Fall & Debug

Single-tap fall simulation. Toggle for real-time debug view of X, Y, Z axes and G-Force.

Testing

Settings

Numpad to enter an emergency GSM contact number. No need for an external device or app configuration.

Configuration

Emergency Countdown

5-second red alert. The user can tap to cancel. If not canceled, it sends an SMS with the GPS location.

Alert

Mobile Application

Companion Flutter app

A cross-platform mobile application that extends the capabilities of the LifeLink watch via a Bluetooth Low Energy connection.

Download Android APK GitHub Project

Live Dashboard

Real-time view of vital parameters mirrored from the bracelet — heart rate (BPM), oxygen saturation (SpO2), impact severity (G-Force), GPS location, and battery level.

❤ BPM
Pulse

O₂ SpO2
Oxygen

G G-Force
Impact

🗺 Map
GPS Tracking

BLE Connectivity

Automatic or manual pairing with the LifeLink bracelet via Bluetooth Low Energy SPP protocol, complete with connection status.

Fall Detection

The app mirrors the bracelet's 3-phase system: Safe → Warning → Alarm, with a 5-second countdown and cancellation capability.

Emergency SOS Response

Upon countdown expiry, it automatically calls the emergency contact, sends an SMS with GPS coordinates, or triggers a system SOS signal.

Interactive Map

Real-time OpenStreetMap representation of the user's location to assist rescuers during an intervention.

Settings

Configure emergency contact, select fall action (Call/SMS/SOS), adjust countdown duration, and set BLE device MAC address.

New Extension

Real-Time Cloud Monitoring

The LifeLink system is now connected to the cloud! Monitor your loved ones from anywhere in the world through our modern Web Dashboard.

MariaDB Cloud

Fast data sync using our own LifeLink Cloud infrastructure.

Live Metrics

Heart rate and SpO2 are updated in real-time without refreshing.

Remote Location

See the exact position on the map even without Bluetooth range.

Fall History

Complete log of all incidents with parameters at the time of fall.

OPEN CLOUD DASHBOARD

LIVE SYNC ACTIVE