Contactless heart monitoring using Doppler radar.

Listen to Your Heart: Doppler Radar Makes Non-Contact Heart Monitoring a Reality

Samir D’Costa in Health & Wellness August 2025 • 4 min read.

"New AI-powered radar tech offers a promising future for remote heart monitoring, providing accurate data without ever touching the patient."

Heart rate variability (HRV) is a key indicator of health, reflecting everything from physical fitness to mental stress levels. Traditionally, monitoring HRV meant being wired up with sensors, but that could be about to change in a big way. Researchers are developing non-contact heart rate (HR) monitoring techniques using Doppler radar, opening up exciting possibilities for remote health tracking.

Doppler radar, known for its use in weather forecasting and speed detection, is now being adapted to sense the subtle movements of your chest caused by your heartbeat. This technology offers a convenient and unobtrusive way to monitor heart health, especially valuable in situations where traditional methods are impractical or uncomfortable.

The challenge? Isolating the faint heartbeat signal from other, stronger signals like breathing and body movements. This is where advanced signal processing and artificial intelligence come into play, helping to filter out the noise and deliver accurate heart rate readings.

How Does Radar Detect Your Heartbeat?

Contactless heart monitoring using Doppler radar.

At its core, the system works by emitting a continuous wave (CW) radar signal towards the person being monitored. This signal reflects off the chest, and any movement – even the tiny displacement caused by a heartbeat – alters the frequency of the reflected wave (this is the Doppler effect in action!). A receiver then captures this reflected signal, and the magic of signal processing begins.

The beauty of this approach lies in its non-invasiveness. No wires, no sensors touching the skin – just a radar unit placed at a short distance away. This makes it ideal for:

Monitoring infants: Especially premature babies who require constant monitoring but are easily disturbed.
Sleep studies: Where wires can disrupt natural sleep patterns.
Elderly care: Offering a simple way to keep track of heart health without burdening the individual.
Fitness tracking: Providing a discreet alternative to chest straps during exercise.

However, the technology faces some tough hurdles. The signal from a heartbeat is incredibly weak, easily drowned out by stronger signals from breathing, fidgeting, or even just shifting in a chair. Traditional methods like Fast Fourier Transform (FFT) and Continuous Wavelet Transform (CWT), while useful, often struggle to pick out the heartbeat signal clearly enough.

The Future of Contactless Heart Monitoring

While challenges remain, the progress in Doppler radar heart monitoring is undeniable. As algorithms become more sophisticated and hardware becomes more refined, we can expect to see this technology playing an increasingly important role in healthcare and personal wellness. Imagine a world where your heart health is continuously monitored without you even noticing – that future may be closer than you think.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.1109/tbme.2018.2878881, Alternate LINK

Title: A Stochastic Gradient Approach For Robust Heartbeat Detection With Doppler Radar Using Time-Window-Variation Technique

Subject: Biomedical Engineering

Journal: IEEE Transactions on Biomedical Engineering

Publisher: Institute of Electrical and Electronics Engineers (IEEE)

Authors: Chen Ye, Kentaroh Toyoda, Tomoaki Ohtsuki

Published: 2019-06-01

Everything You Need To Know

What is Doppler radar and how does it work?

Doppler radar is a technology that detects the subtle chest movements caused by a heartbeat. It works by emitting a Continuous Wave (CW) radar signal that reflects off the chest. The frequency of this reflected wave changes due to the Doppler effect, allowing a receiver to capture the signal. This non-contact method is crucial because it eliminates the need for wires or sensors touching the skin, making it ideal for various applications.

Why is Heart Rate Variability (HRV) important, and how does Doppler radar help?

Heart Rate Variability (HRV) is a significant health indicator, reflecting both physical fitness and mental stress levels. The ability to monitor HRV accurately and unobtrusively is vital. Traditional methods, which require being wired up with sensors, are often inconvenient. Contactless monitoring using Doppler radar offers a more convenient way to track HRV. Accurate HRV monitoring allows for better understanding of an individual's overall well-being.

Explain the process of how Doppler radar detects a heartbeat.

The technology uses a Continuous Wave (CW) radar signal, which is sent towards the person being monitored. This signal reflects off the chest. The tiny displacement caused by a heartbeat alters the frequency of the reflected wave. A receiver captures this reflected signal. Advanced signal processing and Artificial Intelligence (AI) are then used to filter out noise and deliver accurate heart rate readings. This process enables contactless heart monitoring.

What are the main challenges in using Doppler radar for heart monitoring?

The challenges include isolating the faint heartbeat signal from stronger signals like breathing and body movements. Traditional methods like Fast Fourier Transform (FFT) and Continuous Wavelet Transform (CWT) often struggle to clearly pick out the heartbeat signal. This is where advanced signal processing and AI become critical, helping to filter out the noise to provide accurate readings. The signal's weakness makes the process complex.

What is the future of contactless heart monitoring using this technology?

Doppler radar heart monitoring promises to transform healthcare and personal wellness. It provides a convenient and unobtrusive way to monitor heart health, especially in situations where traditional methods are impractical. It's particularly beneficial for monitoring infants, during sleep studies, in elderly care, and for fitness tracking. The continuous advancements in algorithms and hardware will make the technology even more effective and widespread.