Sleep monitoring technologies generally fall into two categories: optical sensing and radar-based sensing.
While both can capture physiological signals, their performance during sleep differs significantly.
This is why SOMNDEEP, a contactless health monitoring system, is built on millimeter-wave radar technology.
Limitations of Optical Sensors During Sleep
Optical sensors typically rely on light to detect blood volume changes beneath the skin.
Although effective in controlled conditions, this approach faces challenges during real sleep scenarios:
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Requires direct skin contact
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Performance depends on consistent placement and pressure
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Susceptible to movement and posture changes
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Can be obstructed by blankets or bedding
During sleep—when users turn, stretch, and adjust naturally—these factors introduce instability.
How Millimeter-Wave Radar Works Differently
Millimeter-wave radar does not rely on light or skin contact.
Instead, it detects micro-movements caused by physiological activity, such as breathing and heartbeat-related motion.
Because radar measures motion rather than surface characteristics, it functions reliably through:
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Clothing
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Blankets
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Normal changes in sleeping posture
This makes radar particularly suitable for overnight monitoring.
Stability in Long-Duration Observation
Sleep monitoring is not about capturing a single moment—it is about observing subtle trends over long periods.
Radar-based systems like SOMNDEEP maintain stability across hours and nights without requiring recalibration or repositioning.
This consistency is difficult to achieve with sensors that depend on precise skin contact.
Summary
While optical sensors have valid applications, they face inherent limitations in sleep environments.
By using millimeter-wave radar, SOMNDEEP’s contactless health monitoring system aligns more naturally with how people actually sleep—delivering stable, unobtrusive monitoring over time.
