| 摘要 |
<p>According to the present invention, there is provided apparatus for use in measuring by infrared absorption measurement the content of CO2 in respiratory gas. The apparatus comprises a holder for receiving a tube for conducting a cyclical respiratory gas flow, heating means in the holder for maintaining the tube at a substantially constant temperature, receiving means for receiving an infrared source, a lens system, a narrow-band interference filter suited to CO2 and a detector for irradiation by the infrared source via the gas flow. The receiving means, the system, the filter and the detector are carried by the holder and aligned with each other. The advantages obtained with this construction consist in that, because of the small dimensions which are possible, the apparatus can easily be connected in the respiratory circuit at a short distance after the mouthpiece without any trouble to the patient. The tube can easily be interchanged and thus meets a sterilisation requirement which is unavoidable for medical equipment. Either it can be sterilised after being taken out, or it can be replaced by a new tube. The tube is simple in construction, need not contain any other devices necessary for operation, and thus is inexpensive.</p> |
