Development of a new system to collect and dry patient exhalation samples for laser photo-acoustic gas analyzer.

The present work is devoted to the development of a new system for collecting and drying patient exhalation samples for a laser photo-acoustic gas analyzer for express analysis of exhaled air, as well as the possibility of ozone sterilization of the gas tract after use. It is proposed to collect the patient's exhalation in a disposable sterile plastic bag, place it in a low-temperature freezer chamber to freeze the water vapor, and then transfer part of the dried exhaled sample to the gas analyzer using a disposable syringe. It is proposed to use ozone purge for 10-15 min to sterilize the gas path. Experimentally, it is shown that the water vapor content in the exhalation samples decreased by ~ 20 times when the packet with samples was kept at a temperature of - 18 °C during 10 min. Cooling the exhalation sample in the packet to - 45 °С and lower will allow reducing the water vapor content at least 200 times from the initial level. A new universal system for collecting and drying of patient exhalation samples for a medical laser photo-acoustic gas analyzer has been developed and tested. A gas path for a medical laser gas analyzer has been designed, which allows sterilization of the internal gas path surfaces using ozone purging.