GB1344862A - Control for use in respiration apparatus - Google Patents

Abstract

1344862 Respiration controllers KOMBINAT MENDIZIN-UND LABORTECHNIK VEB 29 Jan 1971 3524/71 Heading A5T A controller for use in connection with an Ayre's T-piece 26 comprises a two-way valve 10 for connection to the T-piece, a pressure pulse generator 8, a plurality of pneumaticallyoperated logical switching and control elements 5 arranged to control generator 8 which is connected to valve 10 via means 9 responsive to the generator 8 and responsive to said elements 5 for controlling the operation of valve 10 which is adapted for controlling the supply of gas to T-piece 26. Automatic respirator operation is initiated by operating a switch 1 actuating a double-diaphragm relay 4 via a bistable store to thereby supply gas from input 6 to a bistable store 7 of generator 8 which further comprises a shut-off gate 12, choke 13, a chamber 14, pressure limiting units 16, 17 and a pressure limiting unit 15 having an operating threshold pressure between the operating threshold pressures of units 16 and 17 whereby unit 15 supplies pressure pulses from an input 6' via a regulator to an OR gate 9. The pressure pulses each operate valve 10 to pass breathing gas from an input 19 via a choke 20, OR gate 21 and volumeter to an input 24 of T-piece 26 for inspiration by the patient, these pressure pulses also acting via an amplifier 11 and choke 27 to cause a servomotor 28 to close an outlet 30 of T-piece 26 by a valve 29. After each pressure pulse the expiration phases occur during which the valve 29 is open and breathing gas passes from inlet 19 via valve 10 and a choke 23 to an input 25 of T-piece 26 which thereby acts on ejector. Alternating positive-negative breathing is thus automatically effected. Manual operation can be effected by repeatedly operating switch 2. Intermittent positive pressure breathing occurs if choke 23 is completely closed. Anesthetic gas can be supplied during inspiration from an input 38. If regulator 18 is adjusted to above the operating threshold of unit 17 the inspiration period can be infinitely long and the breathing gas flow rate can be adjusted by volumeter. Spontaneous breathing is possible if an aperture 39 of T-piece 26 is opened. T-piece 26 is provided with a monometer 26, a safety valve 35 adjustable to open at -5 to -250 mm. (water column), a valve 33 adjustable to open at +50 to 300 mm., and a valve 24 adjustable to open at a maximum of + 800 mm. Actuation of a switch 31 puts safety valve 33 out 'of operation.