Engineering a One-Wrist ECG Wearable

World's first one-wrist ECG band at an international wearable-health technology company: mobile, firmware, BLE, DSP, electronics, and biomedical signal processing with CES recognition.

2016–2018 · international wearable-health technology company. Published . Updated .

Watch on YouTube: Engineering a One-Wrist ECG Wearable demonstration

Video transcript summary

YouTube auto-captions available; detailed summary provided on this page per FR-30.

Demonstration of a one-wrist ECG band capturing live electrocardiogram traces on-device, showing the compact wrist form factor, electrode contact, and real-time waveform display on a paired mobile interface. The video highlights CES-era prototype hardware and the integrated mobile visualization pipeline.

My role

Mobile Team Lead / Engineer. As the first employee on the initial proof of concept, I helped build wearable biomedical devices from the ground up-mobile stack, signal processing, BLE coordination with firmware, and demo systems for CES-while working with electronics and firmware engineers on wrist-form-factor constraints.

Outcome

Delivered a wrist-worn ECG acquisition system with live ECG waveform visualization on a compact band. It was recognized at CES as a first-of-kind one-wrist ECG form factor for an international wearable-health technology company.

The strongest public evidence for this work is the demonstration video and this case study.

Abstract

I was the first employee working on the initial proof of concept at an international wearable-health technology company. It was a great experience building something completely new from the ground up-establishing early technical foundations and then iterating through several device prototypes, including the one-wrist ECG wearable and a blood-pressure monitoring prototype designed without an air pump.

This case study focuses on that wearable biomedical engineering work: STM32-based acquisition, dry-contact electrode integration, BLE streaming to mobile, and DSP pipelines for live visualization. Work spanned firmware coordination, Java mobile application work, BLE integration, DSP coordination, and device-side C/C++ work, plus demo-hardening for trade-show environments.

Problem

Consumer wearables typically measure PPG-derived heart rate, not a full ECG waveform from a single wrist location. The company needed a demonstrable ECG band that could acquire, process, and display waveforms reliably on mobile while meeting tight mechanical and power constraints.

Constraints

  • Wrist-only electrode geometry, with no chest strap
  • Real-time BLE throughput versus battery budget
  • Trade-show demo reliability (CES)
  • Small team spanning mobile, firmware, and analog front-end

Build

  • Electronics: STM32-based acquisition with modular analog front-end
  • Device / firmware: C/C++ sample timing, packetization, BLE GATT services, and embedded signal-processing paths
  • Mobile: Java Android application work for BLE integration, live visualization, and demo workflows
  • DSP: MATLAB prototyping translated to embedded and mobile filters

Challenges and lessons

  • Early BLE packet loss under crowded RF environments was mitigated with buffering and reconnect logic for demos
  • Inconsistent Bluetooth behavior and API differences across Android manufacturers made reliable device pairing and streaming harder to standardize
  • Silent component replacement during manufacturing affected signal quality and made root-cause analysis more difficult

Results

  • Working one-wrist ECG prototype with live mobile visualization
  • CES recognition for novel form factor
  • Hands-on experience building early wearable biomedical prototypes from proof of concept through subsequent device iterations

Evidence