| 摘要 |
868,606. Respiratory appliances. BRITISH OXYGEN CO. Ltd. Nov. 18, 1959 [Nov. 19, 1958], No. 37184/58. Class 81 (2). A respiratory device particularly for administering anaesthetic gases comprises an expansible reservoir adapted to communicate with the lungs of a patient, a rigid airtight chamber surrounding the reservoir, means for intermittently supplying gas under pressure to the chamber alternately operable with valve means for releasing gas therefrom and loading means associated with the reservoir for causing it to expand when gas is released from the chamber whereby a negative pressure is created in the reservoir. As shown, Fig. 1, a bellows 1 with leads 2 and 3 respectively to and from a patient's face mask &c. is supplied with oxygen or anaesthetic gas by a pipe 7 and is located in a rigid airtight chamber 9, its free end carrying a weight 8. In use, gas under pressure is introduced into the chamber 9 and compresses, the bellows 1 thus forcing a predetermined volume of oxygen past a non-return valve 4 to the lungs until the desired pressure in the lungs has been reached when the pressurizing gas is allowed to escape to atmosphere. The weight 8 moves by gravity to expand the bellows 1 thus creating a negative pressure in the lungs which may be varied by means of an adjustable spring--loaded valve 6 in the respiratory circuit. In another embodiment (not shown), the adjustable spring- loaded valve is located in the pressurizing gas circuit. |
