The Development of a Dual-Radar System with Automatic Hypopnea Threshold Optimization for Contact-Free Sleep Apnea-Hypopnea Syndrome Screening

Figure 1

The dual Doppler radar system. (a) A picture of the main unit and sensors. (b) The sensors were located 20 cm to the left and right of the patient’s midline, near the iliac bone. (c) Schematic of respiration measurement.

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