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Project information

Feasibility study of a capnometry system for the improvement and optimization of outpatient practice

C. Rodríguez-Morcillo A. Cantizano R. Giannetti J.D. Muñoz Frías J. Matanza F.J. Herraiz-Martínez G. López P. Ayala

September 2019 - December 2020

Funding entity IIT

Participated by SUMMA112


In some of the emergencies attended by the SUMMA 112 service, if the patient has a respiratory illness or deficiency, it is necessary to connect him to an automatic respirator that helps him, to a greater or lesser extent, to perform the breathing process in a way optimal In addition, depending on the severity of the patient, it may be necessary to perform a tracheal intubation, which involves inserting a flexible plastic tube through the mouth to the trachea through the throat, if the patient is unable to breathe on his own and is unconscious; or simply use a plastic mask, which is placed on the patient's face covering the nose and mouth, non-invasively, when the patient is conscious and can perform the breathing process by himself, even if it is difficult.
It is necessary to measure the exhaled CO2 (called capnometry) of the patients they attend during an emergency and they must be connected to a respirator, because the retention and accumulation of CO2 in the body can have fatal consequences for the patient.
In addition to capnometry, it is necessary to know the way in which the patient exhales the CO2, which is represented by a curve (called capnography), whose form provides very valuable information to the healthcare staff about the patient's breathing quality. This may indicate an acute respiratory insufficiency, or a decompensation between inspiration and expiration, as well as helping to focus the diagnostic criterion of respiratory failure, among other characteristics.
Depending on the quality of breathing and the amount of CO2 exhaled by the patient, it may be necessary to increase the oxygen pressure (O2) sent to the patient, which allows him to improve the exchange of O2 and CO2 in the lungs. However, increasing the O2 pressure in the automatic breathing system, when a non-invasive mask is used, causes the capnometry and capnography to be altered in such a way that they become totally erroneous data, so they cannot be used to assess the patient's condition.
Because of this, there is a need to develop a capnometer (which includes capnography) that is capable of adequately measuring exhaled CO2, under the condition of high O2 pressure. For this, a feasibility study must be carried out in two complementary aspects: on the one hand, the form of the non-invasive mask used must be analyzed and the modifications made to it must be determined so that the capnographic measure is not altered by pressure of O2. And on the other hand, we must analyze the CO2 sensors on the market and study the feasibility of building a capnograph, small in size, that can be attached to the previous mask (so it has to be small, light weight and electrically autonomous ), and connect with a mobile device (smartphone or tablet type) where to display the patient's capnographic information. Furthermore, we also want to analyze the design of a radiofrequency (RF) sensor, based on metamaterials, which allows the measurement of exhaled CO2 with a completely new technique in the market.


COMILLAS-Capnometria_viabilidad