Respirator device particularly for use in perinatal medicine

A respirator device, particularly for the respiratory treatment of new-born and inmate infants, comprising an oxygen (1) and an air (2) duct coupled respectively to a source of oxygen and pressurized air, a mixing conduit for receiving said oxygen and air, valve means (5, 6) for adjusting the oxygen-air ratio of said mixture, a conduit coupled to said valve means conducting said mixture, a patient junction (17) coupled to said conduit, a controlled beat generator (21) for determining the rhythm of breathing and having an output, a pressure adjusting valve means (24) controlled by the output of the beat generator (21) and coupled to the patient junction for providing adjustable positive pressure threshold levels both during the inspiration and expiration periods, a respiration demand detector (19) comprising an input and an output, said input of said demand detector is coupled to the patient junction (17) for detecting the pressure drop caused by the patient during inspiration, a starting signal generator (20) having an input connected to the output of the respiration demand detector (19) for generating a starting signal in response to the detected pressure drop of each detected inspiration, said starting signal generator (20) comprising an output, said beat generator (21) comprises a sawtooth generator (211) having a trigger input (214), a retriggered input (215) and an astable input (216) and an output wherein said trigger input (214) is associated with assisted respiration;

• said retriggered input (215) is associated with controlled assisted respiration, and said astable input (216) is associated with controlled respiration in absence of spontaneous breathing, a gating circuit (213) comprising three outputs each being coupled to a respective one of said inputs (214, 215, 216) of said sawtooth generator, said gating circuit (213) comprising an input connected to the output of the starting signal generator (20), a respiration stoppage detector comprising an input and output, said output of the starting generator (20) is connected also to said respiration stoppage detector (22) for sensing the presence of spontaneous breathing and for providing a signal in the absence of an output pulse from the starting signal generator (20) within a predetermined period of time, the gating circuit (213) comprises a plurality of enabling inputs, a mode controller (26) for the selection of the operational mode corresponding to the required treatment and having a plurality of outputs connected to respective outputs of said mode controller (26) and accordingly selecting an appropriate one of the trigger, retrigger or astable inputs (214, 215, 216) of the sawtooth generator (211) in accordance with the setting of said mode controller (26) set by the operator, a comparator (212), said pressure adjusting valve means (24) comprising a control input, said output of the sawtooth generator (211) is connected via said comparator (212) to said control input of said pressure adjusting valve means (24), wherein said respiration demand detector comprises a case divided into first and second chambers by a metal membrane, a pressure adjusting assembly, said first chamber communicating with said pressure adjusting assembly and said second chamber communicating with said patient junction means, and further comprises a perforated disc located in said second chamber and confronting said metal membrane, said perforated disc being coated with electrically conductive material such that said metal membrane and said perforated disc comprise a capacitor.

A respirator device, particularly for the respiratory treatment of new-born and inmate infants, comprising an oxygen (1) and an air (2) duct coupled respectively to a source of oxygen and pressurized air, a mixing conduit for receiving said oxygen and air, valve means (5, 6) for adjusting the oxygen-air ratio of said mixture, a conduit coupled to said valve means conducting said mixture, a patient junction (17) coupled to said conduit, a controlled beat generator (21) for determining the rhythm of breathing and having an output, a pressure adjusting valve means (24) controlled by the output of the beat generator (21) and coupled to the patient junction for providing adjustable positive pressure threshold levels both during the inspiration and expiration periods, a respiration demand detector (19) comprising an input and an output, said input of said demand detector is coupled to the patient junction (17) for detecting the pressure drop caused by the patient during inspiration, a starting signal generator (20) having an input connected to the output of the respiration demand detector (19) for generating a starting signal in response to the detected pressure drop of each detected inspiration, said starting signal generator (20) comprising an output, said beat generator (21) comprises a sawtooth generator (211) having a trigger input (214), a retriggered input (215) and an astable input (216) and an output wherein said trigger input (214) is associated with assisted respiration;

• said retriggered input (215) is associated with controlled assisted respiration, and said astable input (216) is associated with controlled respiration in absence of spontaneous breathing, a gating circuit (213) comprising three outputs each being coupled to a respective one of said inputs (214, 215, 216) of said sawtooth generator, said gating circuit (213) comprising an input connected to the output of the starting signal generator (20), a respiration stoppage detector comprising an input and output, said output of the starting generator (20) is connected also to said respiration stoppage detector (22) for sensing the presence of spontaneous breathing and for providing a signal in the absence of an output pulse from the starting signal generator (20) within a predetermined period of time, the gating circuit (213) comprises a plurality of enabling inputs, a mode controller (26) for the selection of the operational mode corresponding to the required treatment and having a plurality of outputs connected to respective outputs of said mode controller (26) and accordingly selecting an appropriate one of the trigger, retrigger or astable inputs (214, 215, 216) of the sawtooth generator (211) in accordance with the setting of said mode controller (26) set by the operator, a comparator (212), said pressure adjusting valve means (24) comprising a control input, said output of the sawtooth generator (211) is connected via said comparator (212) to said control input of said pressure adjusting valve means (24), wherein the starting signal generator (20) comprises a pair of synchronously started astable multivibrators (201, 202), the first astable multivibrator (201) comprises a control input for adjusting the duty cycle being coupled to the output of the respiration demand detector (19), said generator (20) comprises additionally a gating circuit (203) having respective inputs coupled to the outputs of the astable multivibrators (201, 202), and an integrating circuit (204) having an input coupled to the output of the gating circuit (203) and its output forming the output of the starting signal generator (20).