Abstract: A device and a process detect a leak during artificial ventilation of a patient. A measurement system with a sensor arrangement and a sensor fluid guide unit is monitored. A fluid connection is established between a patient-side coupling unit and a medical device with a patient fluid guide unit. A gas sample is branched off from the patient fluid guide unit and guided through the sensor fluid guide unit to the sensor arrangement. A thermal conductivity time course of the gas sample reaching the sensor arrangement is determined with sensor arrangement measured values. Depending on a temporal change in the determined thermal conductivity, a decision is made as to whether there is an indication of a leak between the patient's fluid-guiding unit and the sensor arrangement. The leak establishes a fluid connection between the sensor fluid guide unit and/or the sensor arrangement and the environment.

Abstract: A gas measuring device (1000) for determining the concentration of a gas component in a breathing gas mixture includes a radiation source (1) with a illuminant (2) and a mirror arrangement (3) for emitting light radiation. A sample gas cuvette (5) is formed as a hollow body. A detector arrangement (15) with at least two bandpass filter elements (17, 18) and at least two detector elements (20, 21) receives the filtered light radiation. A control unit (42) is configured to detect signals from the detector elements (20, 21) and determine a concentration of a gas component in the breathing gas mixture. A light guide element (11) is provided in the form of a hollow body.

Abstract: A photoacoustic sensor (100) is capable of detecting a predefined target gas in an area (Um). A process is capable of detecting the target gas with the use of such a sensor (100). A sample chamber (3) holds a gas sample (Gp) to be tested. Electromagnetic waves (eW) from a radiation source (1) pass through the sample chamber (3) and the detection chamber (4). The waves elicit in the detection chamber (4) an acoustic effect, which is measured by an acoustic sensor (7). The acoustic effect is correlated with the concentration of the target gas in the sample chamber (3). The detection chamber (4) is fluid-tightly sealed, is free from target gas and is filled with a replacement gas (Eg). The transmission of the replacement gas (Eg) has a spectral response similar to that of the transmission of the target gas in a predefined target gas wavelength range.

Abstract: A photoacoustic sensor (100) is capable of detecting a predefined target gas in an area (Um). A process is capable of detecting the target gas with the use of such a sensor (100). A sample chamber (3) holds a gas sample (Gp) to be tested. Electromagnetic waves (eW) from a radiation source (1) pass through the sample chamber (3) and the detection chamber (4). The waves elicit in the detection chamber (4) an acoustic effect, which is measured by an acoustic sensor (7). The acoustic effect is correlated with the concentration of the target gas in the sample chamber (3). The detection chamber (4) is fluid-tightly sealed, is free from target gas and is filled with a replacement gas (Eg). The transmission of the replacement gas (Eg) has a spectral response similar to that of the transmission of the target gas in a predefined target gas wavelength range.

Abstract: A process for monitoring a measuring system (110) for mechanical ventilation of a patient (20) is carried out while a fluid connection (40) is established between the patient (20) and a medical device (100). A gas sample is suctioned from the fluid connection (40) and is sent through a gas sensor fluid-guiding unit (52) to a gas sensor array (50). A time curve of the CO2 concentration and O2 concentration in the suctioned gas sample are determined. A concentration change curve of the change over time of the CO2 concentration and the O2 concentration are calculated. A search is made for a time period in which the two concentration change curves continuously have the same sign. Upon detecting such a time period it is checked whether a predefined first leak criterion is met. When this is the case, an indication of a leak (L) is detected.