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Medical Alert Bracelet That Delivers Assistance at the Touch of a Button

Embedded hardware development Embedded software development Firmware development Healthcare IoT Wearable

A hospital is a safe place. But it can't guarantee 24/7 supervision for its residents. A wearable device that can summon assistance in an emergency is a great helper for patients at hospitals or nursing homes. It can substitute for the watchful eye of a doctor, nurse or caregiver, and provide timely assistance to those who need it 

Details of the medical alert bracelet


A healthcare solutions provider for military hospitals and clinics in the USA was looking to build a medical alert device that would integrate into hospital care services. Integra Sources was requested to build this device 


The device is a plastic bracelet with a help button that patients need to wear on their wrist at all times. It notifies hospital staff about an emergency with the patient's condition. It can also detect a patient's fall thanks to a built-in accelerometer.

The device tracks the location of patients when they are in the hospital. In addition, it can transfer data from a patient's personal weight scales and pressure gauge. The data is transmitted over Wi-Fi to the backend server and displayed in the hospital staff console.

One of the main requirements that we needed to meet was to solve the problem of obtaining super-low power consumption for this device. It needed to work for two weeks from a 360 mAh battery. Another technical challenge in this project was receiving the data from the weigh scale, and we successfully overcame this as well.

The medical alert bracelet prototyping process
Medical bracelet prototype development

Technologies used

  • We used NRF52832 with BLE 4.0 support and Cortex-M4 core as MCU in this project.
  • The device has an internal 360 mAh Li-ion rechargeable battery.
  • The device has a button, vibration motor, and 2 LEDs.
  • FreeRTOS was used for firmware development.
  • For WiFi networking, we used Texas Instruments CC3100 IC.
  • Altium Designer IDE was used for Schematics and PCB design.
  • The firmware was implemented using C/C++.
  • Eclipse IDE, GCC compiler, and OpenOCD were used for firmware implementation and debugging.


If a patient feels ill, all they need to do is push the medical alert button on their bracelet and medical assistance will be there as soon as possible. The device sends the signal for help via Wi-Fi or Bluetooth to the nearest access point (i.e. a beacon) which in its turn sends the coordinates of the patient to the server. The server calculates the precise location of the patient in the hospital and sends this information to the medical assistants.

The medical alert bracelet is waterproof. It's charged with a Lithium battery and has a low battery indicator. It is equipped with a vibration motor that lets the patient know whether medical assistants have received the signal for help.

The customer received the device and now is planning to bring the product to the market. They already ordered 300 devices for the hospital.

A medical bracelet prototype and a 3D-printed case
Medical bracelet prototype and 3D printed enclosure 

The time between battery charges

Up to 2 weeks

Device size

40x45x12 mm

INTEGRA SOURCES is incredibly organized and consistently meets project goals. They’re organized and keep good records of all the tasks that are done and need to be done. We met weekly over Skype and also communicate via email. They also implemented a project management tool to track progress. They’re easy to work with, reasonably-priced, and deliver high-quality solutions. The product hasn’t been released yet, but the internal team is extremely pleased with the prototype.

CIO, Healthcare Company

Scope of work

  • Hardware development
  • Firmware development
  • Case development for the device