Validating Force Sensitive Resistor Strip Sensors for Cardiorespiratory Measurement during Sleep: A Preliminary...

Area of Science:

• Biomedical Engineering
• Sleep Medicine
• Wearable Technology

Background:

• Traditional sleep studies like polysomnography are costly and intrusive.
• There is a need for convenient, noninvasive home-based sleep monitoring solutions.
• Accurate measurement of cardiorespiratory parameters is crucial for diagnosing sleep disorders.

Purpose of the Study:

• To develop and validate a low-cost, noninvasive Out of Center Sleep Testing (OCST) system for measuring cardiorespiratory parameters at home.
• To assess the accuracy and reliability of the OCST system compared to reference methods.
• To evaluate the system's performance across different sleep positions and demographics.

Main Methods:

• Utilized two low-cost force-sensitive resistor strip sensors placed under a bed mattress to capture ballistocardiogram signals.
• Employed discrete wavelet transform and Butterworth bandpass filtering for signal processing.
• Recruited 20 healthy subjects (12 males, 8 females) for system validation.

Main Results:

• Achieved a total error of 3.24 bpm for heart rate and 2.32 rates/min for respiration rate.
• Demonstrated minimal dependency on sleeping positions, with the thoracic sensor showing optimal configuration.
• Reported comparable accuracy for male and female subjects.

Conclusions:

• The developed OCST system offers a reliable and unobtrusive method for in-home cardiorespiratory monitoring.
• The system shows potential as a comfortable and cost-effective alternative to traditional sleep studies.
• Further validation with larger, diverse patient groups and frequency bandwidth analysis is recommended.