Respiratory State Estimation Using Trunk Movement Detection

The patent extracts only the essential measurement functions needed for sleep apnea diagnosis from the complex polysomnography system. Specifically, it uses a simple accelerometer to detect body movement during sleep, which is the key indicator for distinguishing obstructive from central sleep apnea. By taking out only the necessary movement detection function, the system achieves accurate diagnosis without requiring the complex full polysomnography setup.

The patent employs a simple, inexpensive accelerometer that can be easily attached to the patient's body during sleep. This disposable-like simple sensor replaces the expensive, complex polysomnography equipment. The accelerometer is sufficient for the specific task of detecting body movement patterns, providing cost-effective and simple sleep apnea screening without requiring hospital infrastructure.

The patent replaces complex mechanical sensing systems (polysomnography with multiple sensors including nasal respiration sensors, abdominal bands) with a simple accelerometer-based mechanical movement detection system. The accelerometer detects body movement patterns that indirectly indicate respiratory status, achieving sufficient precision for distinguishing sleep apnea types without the complexity of direct respiratory measurement hardware.

The patent introduces body movement as an intermediary indicator to indirectly assess respiratory state. Instead of directly measuring respiration (which requires invasive or complex sensors), the system uses body movement detection as a mediator that correlates with respiratory patterns. This intermediary approach enables simple, non-invasive measurement while maintaining diagnostic accuracy for sleep apnea discrimination.