Google has achieved a major milestone in wearable health technology: the Pixel Watch 3 is now the first smartwatch in the U.S. to receive FDA clearance for Loss of Pulse Detection, a feature designed to detect when the wearer’s heart stops beating and alert emergency services if they don’t respond.
Announced in late February 2025 and rolling out to U.S. users in March, this breakthrough reflects the increasing intersection between consumer wearables and medical-grade safety tools. More than just a fitness companion, the Pixel Watch 3 now doubles as a silent guardian for life-threatening emergencies like cardiac arrest, opioid overdose, and sudden respiratory failure.
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How Loss of Pulse Detection Works
The Pixel Watch 3 employs a sophisticated suite of sensors—including optical heart rate, infrared, red light, and motion tracking—to continuously monitor your pulse and movement. Here’s how it responds in a potential crisis:
- Step 1: If the watch detects a complete absence of pulse, it vibrates and displays an on-screen alert asking if you’re okay.
- Step 2: If there’s no interaction, the watch escalates the response by sounding an audible alarm and starting a countdown (around 15–20 seconds).
- Step 3: If there’s still no response, it automatically calls 911, shares your real-time location, and reports the loss of pulse to emergency dispatchers.
This progression from subtle prompt to life-saving call is designed to avoid false alarms while still acting fast when someone becomes unresponsive.
What Makes This Different From Other Smartwatches
While many smartwatches today feature heart rate monitoring or fall detection, Loss of Pulse Detection takes it to another level—detecting when the heart has likely stopped altogether. Until now, this kind of passive cardiac monitoring has been limited to advanced medical devices like implanted defibrillators or hospital-grade wearables. With FDA clearance, Google has opened the door to mainstream adoption of this critical function.
Setup Guide: How to Enable Loss of Pulse Detection
To enable the feature on your Pixel Watch 3, follow these steps:
- Ensure your Pixel Watch 3 and phone are fully updated with the latest software.
- Open the Personal Safety app on the watch.
- Tap on “Loss of Pulse Detection.”
- Follow the on-screen instructions to complete setup, including granting emergency contact permissions and configuring automatic 911 dialing.
This feature was initially introduced in select European markets in 2024 and is now fully functional for U.S. users.
Important Notes Before You Use It
- Eligibility: Google recommends this feature only for users 22 years or older. It’s not intended for people with known heart rhythm disorders who require constant medical monitoring.
- Connectivity: Emergency calls rely on your watch’s cellular connection or a nearby phone with Bluetooth. Without it, help cannot be contacted.
- Accuracy Limitations: As advanced as it is, this feature is not a substitute for professional medical advice or equipment. It’s designed for supplementary protection.
A Step Forward for Smartwatch Safety
This FDA approval is part of a growing trend in the wearable industry: transforming smartwatches from lifestyle accessories into critical healthcare tools. Google is betting that features like Loss of Pulse Detection won’t just appeal to athletes or tech enthusiasts—they could save lives for everyday users in unexpected moments.
As digital health continues to evolve, the Pixel Watch 3 is now one of the most advanced consumer-ready devices on the market for real-time health intervention. Whether you’re a runner, caregiver, or someone with health risks, this new feature may offer peace of mind with a potentially life-saving edge.
Smartwatch Health Feature Comparison
| Feature | Pixel Watch 3 | Apple Watch Series 9 | Galaxy Watch 6 |
|---|---|---|---|
| Loss of Pulse Detection (FDA Cleared) | Yes (FDA Cleared) | No | No |
| Heart Rate Monitoring | Yes | Yes | Yes |
| ECG App (FDA Cleared) | No | Yes (FDA Cleared) | Yes (Korean MFDS only) |
| Blood Oxygen Monitoring | Yes | Yes | Yes |
| Fall Detection | Yes | Yes | Yes |
| Emergency SOS Calling | Yes | Yes | Yes |
| Skin Temperature Sensor | No | Yes | Yes |
| Irregular Heart Rhythm Notifications | Yes | Yes | Yes |
| Sleep Tracking | Yes | Yes | Yes |
| AFib History Tracking | No | Yes | No |
Key Takeaways
- The Pixel Watch 3’s Loss of Pulse Detection feature can identify when your heart stops beating and automatically call for emergency help.
- FDA clearance makes the Pixel Watch 3 the first smartwatch with this unique health safety capability, available in the US starting late March.
- The system includes a 20-second warning period with an audible alarm, allowing users to cancel false alarms by moving or clearing the notification.
Pixel Watch 3 Overview
The Pixel Watch 3 represents Google’s latest advancement in wearable technology, combining health monitoring capabilities with smartwatch functionality. This iteration builds on previous models while introducing groundbreaking features like the FDA-cleared Loss of Pulse Detection.
Brief History and Evolution
Google entered the smartwatch market relatively late compared to competitors, launching the original Pixel Watch in October 2022. The second-generation Pixel Watch 2 arrived in 2023, bringing improved battery life and enhanced health tracking features.
The Pixel Watch 3, released in 2024, marked significant progress in Google’s wearable technology. It integrated more sophisticated sensors and processing capabilities than its predecessors. Google’s acquisition of Fitbit in 2021 continues to influence the health tracking features in the Pixel Watch lineup.
Each generation has refined the circular design that distinguishes the Pixel Watch from more rectangular competitors. The evolution of the watch demonstrates Google’s commitment to creating a comprehensive health and fitness monitoring device.
Key Features and Specifications
The Pixel Watch 3 boasts an array of health monitoring tools beyond the newly FDA-cleared Loss of Pulse Detection. These include:
- Heart rate monitoring with continuous tracking
- ECG (electrocardiogram) functionality
- Fall Detection with automatic emergency services contact
- Irregular Heart Rhythm Notifications
- Car Crash Detection
- Safety Check features
The device features a bright AMOLED display with improved resolution over previous models. Google has also enhanced the battery life, addressing a common criticism of earlier versions.
The Pixel Watch 3 runs on Wear OS, providing seamless integration with Android devices and Google services. It offers customizable watch faces and support for a wide range of apps from the Google Play Store.
Physical fitness enthusiasts benefit from comprehensive workout tracking capabilities and integration with Fitbit’s established fitness ecosystem.
FDA Approval Process
The FDA clearance for Google’s Loss of Pulse Detection feature on the Pixel Watch 3 represents a significant milestone in wearable health technology. This regulatory achievement required rigorous evaluation to ensure the feature’s safety and effectiveness before becoming available to U.S. consumers.
Regulatory Path to Clearance
Google pursued FDA clearance for the Pixel Watch 3’s Loss of Pulse Detection feature through a structured regulatory process. This first-of-its-kind feature underwent extensive testing and validation to prove its ability to detect when a user’s heart stops beating due to conditions like primary cardiac arrest or respiratory failure.
The approval process was notably time-consuming. While the feature had already launched in several European countries, U.S. consumers faced a delay due to the FDA’s stringent requirements. This careful scrutiny ensured the technology met all necessary safety and performance standards before receiving authorization.
The FDA evaluated clinical data demonstrating the feature’s reliability in identifying true loss of pulse events while minimizing false alarms. Google needed to provide comprehensive documentation on the algorithm’s functioning and accuracy rates.
Implications of FDA Clearance
The FDA’s approval enables Google to launch Loss of Pulse Detection in the United States by the end of March 2025. This clearance positions the Pixel Watch 3 as having a potentially life-saving capability that distinguishes it in the competitive smartwatch market.
The approval establishes a regulatory precedent for similar health monitoring features in wearable devices. Manufacturers seeking to implement comparable technologies will likely follow Google’s regulatory pathway.
For consumers, this clearance provides assurance that the Loss of Pulse Detection feature has been evaluated by medical authorities. The feature works by monitoring for pulse absence and, when triggered, initiates a 20-second countdown with an alarm. If the user doesn’t respond, the watch can automatically contact emergency services.
Healthcare professionals may view this approval as another step toward wearable technology becoming a more integrated part of preventative healthcare and emergency response systems.
Advanced Health Monitoring Capabilities
The Pixel Watch 3 introduces cutting-edge health monitoring features that leverage sophisticated sensors and AI algorithms to track vital signs with medical-grade precision. Google’s FDA-cleared technology positions the device as a potential lifesaving tool in emergency situations.
Heart Rate Sensor Integration
The Pixel Watch 3’s heart rate sensor provides continuous monitoring using photoplethysmography (PPG) technology that measures blood flow through the wrist. This advanced sensor works 24/7 to track heart rate patterns and establish personalized baselines for each user.
The newly FDA-cleared Loss of Pulse Detection feature represents a significant advancement in wearable health technology. When the watch detects a complete absence of pulse—potentially indicating cardiac arrest, respiratory failure, or other life-threatening conditions—it triggers an alert sequence.
If no response is detected within 20 seconds, the watch automatically contacts emergency services. The system includes motion detection to reduce false alarms—if the wearer moves or manually clears the warning, the alert is canceled.
This integration of continuous monitoring with emergency response capabilities sets a new standard for smartwatch functionality, transforming the device from a fitness tracker into a proactive health guardian.
Atrial Fibrillation Recognition
The Pixel Watch 3 features sophisticated algorithms designed to identify irregular heart rhythms that may indicate atrial fibrillation (AFib), a common heart condition that can lead to serious complications if left untreated. The watch analyzes heart rhythm patterns during rest periods to detect potential irregularities.
When the device identifies possible AFib patterns, it sends the wearer a notification suggesting they use the ECG app for a more detailed assessment. This early warning system enables users to seek medical advice before symptoms might otherwise become apparent.
Unlike basic fitness trackers, the Pixel Watch 3’s AFib detection has been clinically validated for accuracy. The system minimizes false positives through multiple confirmation checks and extended monitoring periods.
Google’s implementation focuses on both sensitivity (ability to detect actual AFib) and specificity (avoiding incorrect warnings), striking a balance that makes the feature practical for everyday use without causing unnecessary anxiety.
ECG App Functionality
The Pixel Watch 3’s electrocardiogram (ECG) app allows users to record an ECG equivalent to a single-lead electrocardiogram in just 30 seconds. This medical-grade functionality helps detect signs of atrial fibrillation and provides insights into heart rhythm patterns.
To perform an ECG, users simply need to sit still and place their finger on the watch’s digital crown to complete the electrical circuit. The app then analyzes the electrical signals and displays results in an easy-to-understand format.
Results are categorized as either normal sinus rhythm, atrial fibrillation, inconclusive, or poor recording. All ECG recordings are stored in the Pixel Watch health app, where they can be reviewed over time or exported as PDF reports to share with healthcare providers.
The ECG feature complements the Loss of Pulse Detection by offering on-demand cardiac assessment. Together with irregular heart rhythm notifications, these tools form a comprehensive cardiac monitoring system that can identify potential issues before they become emergencies.
Loss of Pulse Detection Feature
The Pixel Watch 3’s revolutionary Loss of Pulse Detection capability represents a significant advancement in wearable health technology. This FDA-cleared feature can identify when a user’s heart stops beating and automatically initiate emergency responses.
Technology Behind Pulselessness Monitoring
The Loss of Pulse Detection system in the Pixel Watch 3 utilizes advanced photoplethysmography (PPG) sensors that continuously monitor blood flow patterns through the user’s wrist. These optical sensors detect subtle changes in blood volume by measuring light reflection from the skin’s surface.
When the watch detects an absence of pulse, sophisticated signal-processing algorithms verify the reading to minimize false alarms. The system must distinguish between a true loss of pulse and temporary sensor disruptions from movement or poor contact.
Once confirmed, the watch activates an emergency protocol. This includes an on-screen alert with a countdown timer allowing users to cancel if it’s a false detection. If not canceled, the watch automatically contacts emergency services with the user’s location data.
Clinical Significance and Use Cases
The Loss of Pulse Detection feature addresses critical health emergencies including primary cardiac arrest, respiratory failure, circulatory collapse, and severe medical events like overdoses or poisoning. This first-of-its-kind technology received FDA clearance on February 26, 2025, marking a significant regulatory milestone.
Medical professionals highlight its potential to reduce response times during cardiac emergencies, where every minute without intervention decreases survival chances by 7-10%. The feature offers particular value for individuals with known cardiac conditions or those living alone.
The technology will roll out to U.S. users by late March 2025, joining 14 other countries where it’s already available. For users with existing medical alert systems, the Pixel Watch 3 provides an additional layer of protection without requiring manual activation.
Emergency Response Integration
The Pixel Watch 3’s FDA-cleared Loss of Pulse Detection feature includes a sophisticated emergency response system that activates automatically when a pulse is lost. This integration connects users directly with emergency services during critical moments when they are unable to call for help themselves.
Automatic Alert System for Emergency Services
When the Pixel Watch 3 detects a loss of pulse, it initiates a multi-step emergency protocol. The watch first displays an on-screen alert with a countdown timer, allowing users to cancel if it’s a false alarm. If there’s no response, the watch activates an audible alert that can help bystanders notice the emergency.
After the countdown expires without user interaction, the watch automatically places an emergency call using the device’s cellular connectivity. This feature works even when the user’s phone isn’t nearby, provided the watch has an active cellular connection.
The system uses the watch’s built-in speaker and microphone to facilitate communication. Google has designed the automatic calling feature to work across 14 countries initially, with U.S. rollout expected at the end of March 2025 following FDA clearance.
Communication with Emergency Medical Services
When contacting emergency services, the Pixel Watch 3 delivers an automated message explaining that the wearer has experienced a possible loss of pulse. This message includes critical information such as:
- The nature of the emergency (loss of pulse)
- The wearer’s current location using GPS coordinates
- Basic identification information if available
The watch’s speaker remains active, allowing emergency dispatchers to hear sounds from the scene. This helps dispatchers assess the situation and determine the appropriate emergency response.
The system is designed to work with existing emergency service infrastructure without requiring special equipment on the responders’ end. Emergency services receive the call like any other 911 call but with the additional automated information that helps expedite an appropriate response.
Additional Safety Features
The Pixel Watch 3 includes a comprehensive suite of safety features beyond the FDA-approved Loss of Pulse Detection. These integrated systems work together to provide users with protection across various emergency scenarios.
Fall Detection and Alerts
The Pixel Watch 3 comes equipped with advanced fall detection technology that can identify when a user experiences a hard fall. Using built-in accelerometers and gyroscopes, the watch can distinguish between normal movements and sudden impacts that might indicate a fall.
When a potential fall is detected, the watch initiates a series of actions. First, it sounds an alarm and displays a prompt asking if the user is okay. If there’s no response within 30 seconds, the watch automatically contacts emergency services.
The system is particularly valuable for elderly users or those with mobility issues. Google has refined the algorithm to reduce false positives while maintaining high sensitivity for actual falls. Users can also manually customize sensitivity levels based on their activity patterns.
Fall detection works even during various physical activities, making it effective for hikers, cyclists, and fitness enthusiasts who face higher fall risks.
Car Crash Detection and Assistance
Car crash detection represents another critical safety feature in the Pixel Watch 3. Using a combination of the accelerometer, GPS, and microphone, the watch can identify the unique motion patterns and sounds associated with vehicle collisions.
When a potential crash is detected, the watch follows a similar protocol to fall detection. It first checks if the user is responsive through on-screen prompts and vibrations. If there’s no response, the system automatically contacts emergency services and shares the user’s location.
Key benefits include:
- Automatic location sharing with first responders
- Provision of relevant medical information to emergency services
- Notification of emergency contacts listed in the user’s profile
The feature functions across various vehicle types and works even in areas with spotty cellular coverage by utilizing satellite connectivity when available.
AI-Based Algorithm for Anomaly Detection
The Pixel Watch 3 employs sophisticated AI algorithms that continuously monitor user health metrics to detect anomalies. These algorithms establish personalized baselines for each user by analyzing typical heart rate ranges, activity patterns, and sleep quality.
When the system identifies significant deviations from established patterns, it can alert users to potential health concerns. For example, it might detect irregular heart rhythms that could indicate atrial fibrillation or other cardiac issues.
The AI system improves over time through machine learning. As it gathers more data about the user, its anomaly detection becomes increasingly accurate and personalized.
Privacy remains a priority, with all sensitive health data encrypted and processed on-device whenever possible. Users maintain control over what information is shared with Google’s servers or healthcare providers.
Safety Check and Check-In Functions
Safety Check allows users to set a timer when entering potentially unsafe situations. If the user doesn’t confirm their safety when the timer expires, the watch automatically shares their location with emergency contacts.
This feature proves particularly valuable for:
- Solo hikers and outdoor enthusiasts
- People walking alone at night
- Individuals meeting someone new
- Anyone entering unfamiliar environments
The complementary Check-In function lets users manually send status updates to designated contacts. These updates can include current location, remaining battery life, and recent activity metrics.
Both features integrate seamlessly with the Google ecosystem, allowing for automatic notifications through multiple channels. Emergency contacts receive alerts via text, email, or through their own Google devices.
Users can customize these functions extensively, setting different protocols for various situations and contact groups.
Comparison with Competitors
The Pixel Watch 3’s FDA-cleared Loss of Pulse Detection feature represents a significant advancement in smartwatch health technology, positioning it uniquely in the competitive landscape of wearable devices focused on potentially life-saving features.
Pixel Watch 3 vs. Apple Watch
The Pixel Watch 3’s Loss of Pulse Detection capability sets it apart from Apple Watch, which currently offers fall detection and crash detection but lacks specific pulse loss monitoring. While Apple Watch Series 9 and Ultra 2 provide comprehensive health monitoring with ECG and irregular heart rhythm notifications, Google’s innovation specifically targets the critical scenario when a heart stops beating.
Apple Watch maintains advantages in its broader ecosystem integration and longer market presence. However, the Pixel Watch 3’s new feature addresses a critical health emergency scenario that even Apple hasn’t tackled yet.
The implementation differs significantly too. When the Pixel Watch 3 detects a loss of pulse, it sounds an alarm with a 20-second countdown and can automatically call emergency services if the user doesn’t respond. This targeted approach to cardiac emergencies could influence consumer choices, especially for those with heart health concerns.
This first-of-its-kind feature could potentially save lives in cases of primary cardiac arrest, respiratory failure, or even overdose situations – applications beyond what current Apple Watch models offer.
Potential Impact on Public Health
The FDA approval of the Pixel Watch 3’s Loss of Pulse Detection feature represents a significant advancement in wearable health technology. This feature can detect when a user’s heart stops beating due to conditions like primary cardiac arrest, respiratory failure, or circulatory failure.
For cardiac arrest victims, timing is critical. The American Heart Association notes that survival rates decrease by 7-10% for every minute without treatment after cardiac arrest occurs. The Pixel Watch 3 could help bridge this critical time gap.
The watch triggers an alarm and initiates a 20-second countdown when it detects a loss of pulse. If the user doesn’t respond, it can automatically contact emergency services.
This technology may be particularly valuable for individuals with known heart conditions or those at risk of overdose or poisoning. Early detection could mean the difference between life and death in these situations.
Potential Benefits:
- Faster emergency response for cardiac events
- Improved survival rates for heart attack victims
- Timely intervention for overdose and poisoning cases
- Enhanced monitoring for those with circulatory issues
Health experts believe wearable technology like this could supplement traditional healthcare by providing continuous monitoring outside clinical settings. This represents a shift toward preventative and responsive care.
The feature could be especially important for people living alone or in remote areas where immediate medical assistance isn’t readily available. For these individuals, automated emergency calls could be life-saving.
However, the technology is not a replacement for medical care. Users should understand its limitations and continue seeking professional medical advice for health concerns.
User Experience and Accessibility
The Pixel Watch 3’s FDA-approved loss of pulse detection feature enhances both user safety and accessibility through thoughtful design choices. The watch balances advanced health monitoring with user-friendly interfaces while maintaining reliable performance.
Ease of Use and Interface Design
The Pixel Watch 3 implements an intuitive alert system for its loss of pulse detection feature. When the watch detects a potential emergency, it displays clear visual warnings with bright red lights flashing to grab attention. The interface provides a straightforward 20-second countdown timer giving users time to dismiss false alarms.
Users can easily cancel alerts through simple taps or movement detection. This design prevents unnecessary emergency calls while ensuring genuine emergencies receive prompt attention.
The watch face displays health metrics in easy-to-read formats with high-contrast visuals suitable for users of various ages and visual abilities. Google has optimized the touch sensitivity to work even with slight movements, making it accessible to those with limited dexterity.
Reliability and Battery Life
The loss of pulse detection system uses multiple verification methods to minimize false alarms. The watch combines heart rate monitoring with a motion sensor to confirm whether a user is truly unresponsive or simply in deep sleep.
Battery optimization allows the critical health monitoring features to function even in low-power states. Most users report 24-36 hours of battery life with health monitoring active, though this varies based on usage patterns.
Google implements regular firmware updates to improve detection accuracy and battery efficiency. The company claims 99.7% accuracy in test environments, though real-world performance may vary slightly.
The emergency call feature maintains reliability even in areas with weaker cellular connections by prioritizing emergency services traffic.
Customer Feedback and Testimonials
Early adopters praise the non-intrusive nature of the pulse detection system. Many users report feeling increased security, particularly those with known heart conditions or who live alone.
Some customers have noted occasional false positives during deep sleep, though these instances decreased with software updates. The majority appreciate the simple cancellation process for false alarms.
Professional caregivers have begun recommending the device for elderly patients as an alternative to traditional medical alert systems. Several users have shared positive experiences with the automatic emergency notification system during genuine health events.
Community forums highlight the feature’s potential life-saving capabilities while acknowledging the importance of proper watch positioning for accurate readings. Most users find the wrist-based monitoring comfortable enough for 24/7 wear.
Frequently Asked Questions
The Pixel Watch 3’s FDA-approved health monitoring features represent significant advancements in wearable technology for emergency health situations. Users have questions about how these features work and their practical applications in daily life.
What are the FDA-approved health monitoring features of the Pixel Watch 3?
The Pixel Watch 3 has received FDA clearance specifically for its Loss of Pulse Detection feature. This groundbreaking capability will be available to US customers starting at the end of March 2025.
Unlike some other health monitoring features, Loss of Pulse Detection is designed for emergency situations when a person’s heart suddenly stops beating.
The FDA clearance marks an important milestone for Google’s wearable technology in the health monitoring space.
How does the Pixel Watch 3 detect a loss of pulse?
The Pixel Watch 3 uses its sensors to continuously monitor the wearer’s pulse. When the device cannot detect a pulse, it initiates the Loss of Pulse Detection protocol.
Upon detecting a potential pulse loss, the watch sounds an alarm and begins a 20-second countdown. This gives users a chance to respond if it’s a false alarm.
If the user doesn’t clear the warning or show movement during this countdown, the watch determines they may be experiencing a genuine emergency and can automatically contact emergency services.
Can the Pixel Watch 3 monitor for heart rate irregularities such as atrial fibrillation?
While the Pixel Watch 3’s primary FDA-cleared feature is Loss of Pulse Detection, it maintains standard heart rate monitoring capabilities common in modern smartwatches. However, specific FDA clearance for atrial fibrillation detection hasn’t been announced.
The watch focuses on identifying complete loss of pulse rather than specific heart rhythm abnormalities. This distinction is important for users to understand the scope of the watch’s capabilities.
Users with known heart conditions should consult healthcare providers about appropriate monitoring devices.
What steps should be taken if the Pixel Watch 3 alerts to a potential loss of pulse incident?
If conscious when the watch triggers an alert, users can clear the warning within the 20-second countdown if it’s a false alarm. Movement will also indicate to the watch that the user isn’t experiencing an emergency.
If the user doesn’t respond, the Pixel Watch 3 can automatically place a call to emergency services on behalf of the unconscious wearer. This automated emergency response is a critical feature for situations where the user cannot call for help themselves.
Bystanders should prepare to administer emergency first aid while waiting for professional medical assistance to arrive.
How accurate is the Pixel Watch 3 in detecting pulse loss compared to other FDA-approved devices?
Google has not published comparative accuracy statistics between the Pixel Watch 3 and medical-grade pulse detection devices. The FDA clearance indicates the feature meets necessary standards for consumer health technology.
The watch uses consumer-grade sensors rather than medical-grade equipment, which may affect its sensitivity and specificity compared to devices designed specifically for medical settings.
Users should understand that while FDA-cleared, the Pixel Watch 3 is not a replacement for medical devices prescribed by healthcare professionals for those with known health conditions.
Are there any guidelines provided by the manufacturer on the use of Pixel Watch 3 for health monitoring purposes?
Google emphasizes that the Loss of Pulse Detection feature is designed as a safety net rather than a primary medical monitoring device. It can help in unexpected emergencies affecting people of any age.
The company notes that pulse loss can result from various causes including cardiac arrest, respiratory failure, circulatory failure, overdose, or poisoning. This highlights the feature’s broad potential application.
Users should review the manufacturer’s documentation for proper wear instructions to ensure optimal sensor contact and accurate readings.
