ECG Holter — Portable Long-Term Cardiac Monitoring Device
We developed a compact, medical-grade ECG Holter monitor for continuous 24–72 hour cardiac recording outside clinical settings. The device captures multi-lead ECG signals at 500 Hz with 16-bit resolution, stores them on an SD card, and runs automated arrhythmia detection algorithms — enabling cardiologists to identify intermittent events that a brief office ECG would miss entirely.
Category:
MedicalIndustry:
Medical DevicesYear:
2024The Challenge
Many serious cardiac conditions — paroxysmal arrhythmias, intermittent atrial fibrillation, brief ST-segment changes — occur unpredictably and are invisible to standard 12-second ECG tests performed in clinic. Existing Holter devices were bulky, uncomfortable for multi-day wear, and lacked on-device intelligence, placing the entire analysis burden on post-processing software and physician review time. Patients needed a recorder that was lightweight, wearable through daily activities, and capable of flagging events automatically in real time.
Our Solution
We designed a wearable ECG Holter with a 3-lead (expandable to 12-lead) analog front-end delivering medical-grade signal quality with active 50/60 Hz rejection and motion artifact suppression. An STM32 microcontroller running optimized low-power firmware manages continuous 500 Hz sampling, on-device arrhythmia detection algorithms, and SD card storage with compression — sustaining 24–48 hours of recording on a rechargeable Li-ion cell. A patient event-marking button timestamps symptom reports directly in the recording. PC software handles ECG visualization, automated HRV and arrhythmia analysis, and physician report generation.
Key Features
- 24–72h Continuous ECG Recording: 500 Hz sampling rate, 16-bit ADC, SD card storage with compression — capturing up to 72 hours of clinical-quality cardiac data on a single charge.
- Real-Time Arrhythmia Detection: On-device algorithms continuously analyze the incoming ECG stream, flagging arrhythmias, ectopic beats, atrial fibrillation episodes, and ST-segment deviations without post-processing delay.
- Medical-Grade Analog Front-End: Low-noise, high-CMRR amplifiers with active 50/60 Hz notch rejection and motion artifact mitigation deliver signal quality equivalent to clinical-grade equipment.
- Patient Event Marking: A dedicated button timestamps patient-reported symptoms directly in the recording, letting physicians correlate subjective events with the ECG waveform at the exact moment they occur.
- HRV & Advanced Analysis: Companion PC software computes heart rate variability (time-domain and frequency-domain), detects arrhythmia burden, and generates structured physician reports from the recorded session.
- Lightweight Wearable Form Factor: Ergonomic, waterproof enclosure designed for comfortable continuous wear through sleep, exercise, and daily activities — maximizing patient compliance over the full recording window.
Technologies
- STM32
- ECG AFE (ADS1292)
- SD Card
- 16-bit ADC
- 500 Hz Sampling
- USB CDC
- Li-ion Battery
- C
- PC Analysis Software
Results
The ECG Holter device brings clinical-grade cardiac monitoring to a wearable form factor — capturing intermittent events that would otherwise go undetected, reducing physician review burden through automated detection, and enabling confident diagnosis from days of continuous data rather than seconds.
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