Noncontact respiration rate monitoring based on sensing exhaled air

Abstract

Respiration rate is the average number of times air is inhaled and exhaled per minute. Respiration rate is an important indicator of a person’s health and therefore, it needs to be measured accurately. Existing respiration monitoring systems are generally contact based that means the sensing element needs to be attached to the subject's body. The attached sensor can cause distress in some children, affecting their respiration rate. The device can also become dislodged interrupting the monitoring. This work presents an air flow sensing approach to noncontact respiration rate monitoring. The exhaled air is guided through a small funnel to a chamber that contains a heating element. The heated air leaves the chamber and is then detected by a thermistor that converts the air flow temperature variations to an electrical signal. The signal is amplified, filtered and digitised. Signal processing techniques are used to extract respiration rate from the signal in real time. The device provides respiration rate at distances from 15 to 30 cm from the subject’s face.

COVID-19 symptom identification using Deep Learning and hardware emulated systems

“…Even though the study proposed by Alkali et al (2014) maintains a contactless approach, the hardware component must be placed sufficiently close to the person’s nasal area. Therefore, the end that is exposed to the person may contain virus particles transmitted through an infected person.…”

Thermal image processing for real‐time non‐contact respiration rate monitoring

“…There were a number of studies to develop non-contact respiration rate monitors based on technologies such as video imaging, ultrasound and radar detection and air flow measurement [9][10][11][12][13][14][15][16][17]. Video monitoring tracks chest and abdominal movements.…”

Infrared Imaging for Real-Time Noncontact Respiration Monitoring

“…In the former, a device is attached to the subject's body, while in the later physical contact is not required. In both types, the monitoring is performed through utilisation of an effect that is produced as a result of respiration [5]. The most common effects are changes in abdomen and chest position, changes in the temperature of expired and inspired air, changes in expired air flow and variations in infrared emission from the skin surface centred on the nose and mouth.…”

“…The most common effects are changes in abdomen and chest position, changes in the temperature of expired and inspired air, changes in expired air flow and variations in infrared emission from the skin surface centred on the nose and mouth. These were utilised in different studies to measure respiration rate [2,[5][6][7][8][9][10][11][12].…”