Advantages of Pressure Sensors for CPAP Equipment

Obstructive Sleep Apnea (OSA) is a serious condition where one’s airway is repeatedly blocked while asleep. It is estimated that about 22 million Americans* suffer from this disorder. To treat OSA, a physician may prescribe a Continuous Positive Air Pressure (CPAP) device. This device helps maintain a positive air pressure in order to prevent the patient’s tongue or soft palate from blocking air passage into the back of the throat. A high end CPAP device utilizes a pressure sensor to control the prescribed pressure settings that are then generated by a blower. An additional advantage of integrating a pressure sensor is its ability to detect snoring. A high pressure setting will open the airway but may cause discomfort as it impedes exhalation. Since many people snore before experiencing apnea, a pressure sensor that is able to detect snoring can be used to define a pressure setting just above the snoring trigger point and reduce discomfort during exhalation.

Most gauge pressure sensors used in CPAP devices are digital, and thus have a predefined update rate which is often not fast enough to capture snoring events. Mitsumi’s MMR920 offers selectable SPI or I2C digital outputs, has an update rate of 0.4ms, and has been proven to capture snoring events.  Additionally the sensor includes a data ready signal for the I2C bus to optimize microcontroller communication. The MMR920 is an ideal pressure sensor for CPAP applications. See the video for details.

*Source: American Sleep Apnea Association