Camera-based system for contactless monitoring of respiration

Abstract

Reliable, remote measurement of respiration rate is still an unmet need in clinical and home settings. Although the predictive power of respiratory rate for a patient's health status is well-known, this vital sign is often measured inaccurately or not at all. In this paper we propose a camera-based monitoring system to reliably measure respiration rate without any body contact. A computationally efficient algorithm to extract raw breathing signals from the video stream has been developed and implemented. Additionally, a camera offers an easy access to motion information in the analyzed scenes, which significantly improves subsequent breath-to-breath classification. The performance of the sensor system was evaluated using data acquired with healthy volunteers, as well as with a mechanical phantom, under laboratory conditions covering a large range of challenging measurement situations.

Remote monitoring of breathing dynamics using infrared thermography

“…Doppler radar [1] and visible/near infrared image sensors [11]) to measure breathing activity. Together with IRT, these two technologies have demonstrated a great potential to detect this important vital parameter.…”

“…by using electrical impedance tomography -EIT) [16,17] or (4) performing signal analysis from electrocardiography (ECG) [11,18,19]. Moreover, there are more precise but also more invasive methods available such as capnography [19], monitoring varying partial pressure of carbon dioxide (CO 2 ) in tidal volume, as well as spirometers [11] and nasal thermistors [3] measuring air-flow and nasal temperature variations, respectively.…”

“…They require attachments of sensors to the patient, leading to discomfort, stress and even to soreness, particularly in small children [10]. In general, monitoring of BR can be performed by (1) measuring chest or chestabdomen movement with respiratory belt transducers [11,12], (2) detecting acoustic signals of the upper airway which occur due to turbulent airflow [13][14][15], (3) metering electrical impedances of the thorax (e.g. by using electrical impedance tomography -EIT) [16,17] or (4) performing signal analysis from electrocardiography (ECG) [11,18,19].…”

“…Therefore, new monitoring solutions based on Doppler radar [1] and imaging sensors (visible [11], midwave infrared [12] and long wave infrared imaging sensors [10,20]) have been being proposed and developed.…”

“…In general, monitoring of BR can be performed by (1) measuring chest or chestabdomen movement with respiratory belt transducers [11,12], (2) detecting acoustic signals of the upper airway which occur due to turbulent airflow [13][14][15], (3) metering electrical impedances of the thorax (e.g. by using electrical impedance tomography -EIT) [16,17] or (4) performing signal analysis from electrocardiography (ECG) [11,18,19]. Moreover, there are more precise but also more invasive methods available such as capnography [19], monitoring varying partial pressure of carbon dioxide (CO 2 ) in tidal volume, as well as spirometers [11] and nasal thermistors [3] measuring air-flow and nasal temperature variations, respectively.…”