Apple's Detachable Watch Patent // Redefining Continuous Health Monitoring

March 18, 2025

Apple's Detachable Watch Patent // Redefining Continuous Health Monitoring

Apple has been granted a groundbreaking patent for a future Apple Watch featuring a detachable watch body that allows health sensors embedded in the band to continue monitoring a user's vital signs even when the main watch unit is removed. This design could transform how users interact with wearable health technology by solving a persistent challenge: maintaining continuous health monitoring during charging cycles and other situations when wearing the full watch is impractical.

The patent, officially granted by the U.S. Patent and Trademark Office on March 18, 2025, represents a major evolution in Apple's wearable strategy and could position the company’s health monitoring capabilities closer to dedicated fitness trackers like Whoop, which focus on uninterrupted biometric tracking.


The Patent's Core Innovation: Splitting Functions Between Watch Body and Band

The newly granted patent describes a smartwatch system consisting of two key components that can function both together and independently: a detachable watch body and a sensor-equipped band. This approach addresses several limitations of current wearable technology by dividing functionality between the two elements based on how frequently certain features are needed.

Apple Patent

According to the patent, the band would house sensors necessary for continuous health monitoring, allowing it to remain on the user’s wrist while the main watch body—containing the display, processor, and other power-intensive components—can be removed for charging or during activities where a full watch might be cumbersome.

"Systems of the present disclosure can provide a watch with a watch body and a band device that can be used together or independently of one another," states the patent. "The band device can provide continual operation of its functions even in the absence of the watch body."

This design eliminates a key problem with current smartwatches: removing the watch for charging results in gaps in health data collection, which can be particularly problematic for sleep tracking and continuous heart rate monitoring.


Facilitating Multiple Operation Modes

A key aspect of the patent is its focus on facilitating operation in multiple modes to provide flexibility while maintaining core health tracking functionality. This modular approach signals a shift in wearable design, where smartwatches evolve into more adaptable systems.

The patent explains: "Neither the watch body nor the band device need to independently include components that provide every function that will be desired by the user. Instead, functions that are desired on a continual or long-term basis can be provided by the band device, and functions that are desired on an intermittent or short-term basis can be provided by the watch body."


Real-World Applications and User Benefits

Uninterrupted Health Monitoring During Charging

One of the biggest advantages of this design is the ability to continue health monitoring even while the main watch body is charging. Currently, Apple Watch users must remove the entire device to charge, leading to gaps in biometric data. With health sensors remaining on the wrist, users could maintain continuous tracking of key health metrics.

This would be particularly valuable for conditions that require constant data collection, such as heart rhythm irregularities or sleep apnea monitoring.

Enhanced Sleep Tracking Comfort

The detachable design could greatly improve the Apple Watch’s sleep tracking experience. Many users find the current watch too bulky for comfortable overnight wear. With a sensor-equipped band, users could detach the main watch body at night while still capturing essential sleep data.

Extended Battery Life for Critical Functions

Separating core health monitoring from power-hungry features like the display could allow the band to operate for much longer periods between charges. This approach mirrors the functionality of fitness trackers like Whoop, which prioritize long-term biometric tracking over smartwatch features.

Versatility for Different Activities and Occasions

The modular design also provides flexibility for different activities. Users could remove the watch body for formal occasions while still tracking activity and health metrics. Similarly, during workouts, some may prefer the lighter weight of just the band.


Technical Implementation and Challenges

Power Management and Battery Life

A major challenge will be ensuring adequate power supply for the band when it operates independently. The patent mentions "power sharing" between the watch body and band, suggesting some form of energy transfer. However, when the components are separated, the band would require its own battery and ultra-efficient power management.

Apple Patent

Sensor Technology and Placement

The patent does not specify exactly which sensors will be embedded in the band, but based on Apple’s existing technology and prior patents, likely candidates include:

  • Heart rate monitor (PPG)
  • Electrocardiogram (ECG)
  • Blood oxygen (SpO2)
  • Temperature sensors
  • Accelerometers for activity tracking

Apple has previously explored integrating ECG and blood pressure monitoring directly into the watch band, indicating that advanced sensor integration is part of its long-term strategy.

Data Storage and Synchronization

When the watch body is detached, the band must store health data until it can sync with the full watch. This requires onboard memory and a seamless data transfer process upon reconnection.


Comparison to Existing Technologies

The Whoop Approach

The Whoop fitness tracker is a prime example of a wearable focused exclusively on continuous health monitoring. Whoop operates without a screen, offering 24/7 tracking for strain, recovery, and sleep.

Apple’s patent suggests a hybrid approach—combining Whoop-style continuous monitoring with the full smartwatch experience. This could appeal to both fitness enthusiasts who need uninterrupted data and casual users who want smartwatch features.

Current Apple Watch Limitations

Apple’s existing watches have gaps in health monitoring due to battery life constraints. For example, the blood oxygen sensor on current models takes intermittent readings rather than continuous tracking. A sensor-equipped band could enable more frequent measurements, providing deeper health insights.


Broader Context: Apple’s Health Monitoring Strategy

Evolution of Apple’s Health Sensors

Apple has steadily expanded the health capabilities of its smartwatches, from ECG functionality in the Series 4 to blood oxygen monitoring in later models. This patent suggests that Apple aims to address continuous monitoring gaps while improving user comfort.

Expanding Apple’s Patent Portfolio

Apple has filed multiple patents related to health-focused wearables, including:

  • A patent for stretchable fabric-based bands with built-in sensors
  • A patent for respiration rate measurement through wearable devices
  • A patent for continuous watch bands designed for enhanced sensor accuracy

These filings indicate a long-term commitment to wearable health innovation.


Patent Disputes and Legal Challenges

The Masimo Dispute

Apple recently faced a lawsuit from medical technology company Masimo over its blood oxygen sensor, leading to temporary sales restrictions of the Apple Watch Ultra 2 and Series 9 in the U.S.

The AliveCor Case

AliveCor sued Apple over ECG functionality, though the lawsuit was ultimately dismissed after the patents were ruled unpatentable.

These legal battles highlight the complexity of health-related patents and could influence Apple’s future wearable innovations.


Future Implications and Market Impact

Potential Release Timeline

Patents often take years to materialize in commercial products, if at all. However, given the strong user benefits and Apple’s focus on health tracking, this concept could appear in a future Apple Watch model.

Market Differentiation

If implemented, this technology could give Apple a major advantage over competitors like Samsung and Google, whose smartwatches still require full removal for charging.

Expanding Apple's Health Ecosystem

Continuous monitoring would enhance Apple’s growing health platform, providing more comprehensive biometric data for both individual users and healthcare providers.


Technical Considerations for Implementation

Secure Attachment Mechanism

Apple must design a connection system that is secure yet easy to detach for everyday use.

User Interface Adjustments

If the main watch body is detached, the band would need alternative ways to notify users of health alerts, such as haptic feedback or small indicator lights.

Material and Design Challenges

Creating a band that houses advanced sensors while maintaining comfort and durability presents significant engineering challenges.


Conclusion

Apple’s patent for a detachable Apple Watch with continuous health monitoring represents a potential breakthrough in wearable technology. By separating core functions into a modular system, Apple could solve key pain points such as charging interruptions, sleep tracking comfort, and long-term health data continuity.

While technical challenges remain, the potential benefits for users are significant. If Apple brings this concept to market, it could redefine how smartwatches approach health tracking—offering a seamless blend of functionality, flexibility, and continuous biometric monitoring.

The smartwatch industry is evolving, and Apple's innovative patent suggests the next step: a future where wearable health technology is not only smarter but also more adaptable to users’ real-world needs.