Nasal cavity temperature measurement for non-invasive respiratory rhythm monitoring and its interfacing with computer

Traditionally monitoring systems for respiratory care are classified into invasive and non-invasive methods. The former refer to measurement systems that penetrate the body, while the latter consider the systems that rest on the skin or those using samples of inspired or expired gases[10]. Among the so called non invasive techniques this technique is based on the measure of temperature at the patients airway. It is usually used in intubated patients, or applied in its modified version using a nasal cannula for non intubated patients. The method measures the temperature changes in the inhalation-exhalation cycle. In this method efficiency is limited since humidity, secretions and other factors distort the resulting signal. Other methods measuring the patient's CO2 in/out flow are based on Capnography, using a Capnographic sensor. The method measures the CO2 at the patients airway.