Apnea discrepancy between Sleep Mat and CPAP machine

Hello @Doug H,

Thank you for reaching out ot us. It is great to see you’re using both the Sleep Analyzer and a CPAP machine to stay on top of your respiratory health.

That is quite a significant difference in readings (30 vs. 2 events per hour). While it might seem like the mat is "over-reporting," the discrepancy is often due to the fact that these two devices measure your breathing using completely different methods.

• Pneumatic vs. Airflow Sensing: Your CPAP machine measures airflow directly through your mask. It is very good at seeing if air is moving, but it can sometimes miss "hypopneas" (shallow breathing) or "respiratory effort-related arousals" if the pressure is successfully splinting the airway open, but your body is still struggling to breathe.
   
• Ballistocardiography (BCG): The Sleep Analyzer uses a pneumatic sensor under your mattress to measure the mechanical waves of your heartbeat, breathing, and body movement. It is highly sensitive to the effort your chest is making to breathe.
   
• A "Handshake" Issue: Currently, the Sleep Analyzer is not specifically optimized for use alongside a CPAP machine. We are currently investigating the use of the Withings Sleep with different CPAP devices. Sleep has not been yet tested for use during CPAP treatment. A scientific protocol is currently ongoing in CPAP users to compare AHI (Apnea-Hypopnea Index) given by CPAP devices and the WSA (Wake-Sleep Algorithm).
   

We are currently investigating how the Sleep Analyzer interacts with various CPAP devices to improve accuracy for users like yourself. In the meantime:

1. Placement Check: Ensure the mat is positioned exactly at chest level and is not being affected by any CPAP hoses resting on the bed, as the vibrations from the hose can sometimes interfere with the sensors.
    
2. Consult Your Specialist: Since your CPAP reports a very healthy 2 AHI, but the mat detects 30, it is worth sharing both reports with your sleep doctor. They can determine if the mat is catching "residual" events that the CPAP isn't logged, or if the CPAP's presence is simply creating a "false positive" for the mat's sensors.
    
3. Reach Out to Us: Please join our Live Chat here.. Our technical team would love to gather more details about which CPAP model you are using, as this helps our engineers refine the algorithm for users with sleep apnea therapy.
    

We want you to feel confident in your data, and we appreciate you helping us bridge the gap between these two technologies.

Regards,

Win, Withings Customer Service