Device and process for supplying respiratory gas under pressure or volumetrically

Abstract

A device for supplying respiratory gas to a patient according to respiratory cycles, includes a gaseous flow rate generator provided with a turbine with low inertia and high nominal speed, a first supply circuit for the gaseous flow toward a respiratory mask or an intubation elements of the patient, elements for measuring pressure and/or measuring flow rate of the gaseous flow, the computation elements for parameters of pressure and/or flow rate, and elements for controlling the speed of rotation of the generator. The measuring elements, the computation elements and the speed control elements coact automatically to control the speed of rotation of the turbine as a function of the inspiration and expiration phases and as a function of patient pressure signals and/or inspiration flow rate signals.

1 . Device ( 1 ) for supplying respiratory gas to a patient according to respiratory cycles, comprising a gas flow generator ( 2 ) provided with a turbine ( 2   a ) with low inertia and high nominal speed, a first circuit ( 3 ) called a circuit for supplying a gaseous flow to a respiratory mask ( 4 ) or to an intubation means of the patient, means ( 5 ,  6 ,  7 ,  8 ) for measuring the pressure and/or flow rate of the gaseous flow, means ( 9 ) for computing parameters of pressure and/or flow rates and means ( 10 ) for controlling speed of rotation of the generator, characterized in that the measuring means ( 5 ,  6 ,  7 ,  8 ), the computation means ( 9 ) and the means ( 10 ) for controlling the speed coact automatically to control the speed of rotation of the turbine ( 2   a ) as a function of the inspiration and expiration phases and as a function of the patient pressure signals and/or inspiration flow rate signals.  
   
   
       2 . Device according to  claim 1 , characterized in that the pressure measuring means comprise a sensor ( 6 ) of patient pressure and/or a sensor ( 7 ) of expiration valve pressure.  
   
   
       3 . Device according to  claim 1 , characterized din that the flow rate measuring means comprise a sensor ( 7 ) of inspiration flow rate disposed adjacent the outlet of the generator ( 2 ).  
   
   
       4 . Device according to  claim 1 , characterized in that it comprises a passive member ( 12 ) for generation of a pressure drop in the supply circuit.  
   
   
       5 . Device according to  claim 4 , characterized in that this passive member ( 12 ) is a non-return flap if desired associated with a passive flap ( 13 ) for the addition of external air downstream of the non-return flap in the supply circuit ( 3 ).  
   
   
       6 . Device according to  claim 1 , characterized in that it comprises a second circuit ( 16 ) comprising a proportional electro-valve ( 15 ), for controlling an expiration valve ( 14 ) that is part of a third circuit ( 11 ) by application of a counter-pressure to this valve ( 14 ), control means of said proportional electro-valve ( 15 ) being coupled to the computation means ( 9 ).  
   
   
       7 . Device according to  claim 1 , characterized in that the means for measuring flow rate comprise an expiration flow rate sensor ( 8 ) in the third circuit ( 11 ) so-called patient return circuit.  
   
   
       8 . Process for supplying a respiratory gas according to respiratory cycles, comprising inspiration and expiration phases, by means of a device according to  claim 1 , characterized in that the measuring means ( 5 ,  6 ,  7 ,  8 ) and the computation means ( 9 ) act on the speed control means ( 10 ) so as automatically to control the speed of rotation of the turbine ( 2   a ) as a function of pressure and/or volume standards, of the detection of the inspiration and expiration phases, of patient pressure signals and/or inspiration flow rate signals, the supplying of the respiratory gas taking place as to pressure and/or as to volume.  
   
   
       9 . Process according to  claim 8 , characterized in that it comprises phases of pressure increase with increase slopes of pressure produced by acceleration of the turbine ( 2   a ).  
   
   
       10 . Process according to  claim 8 , characterized in that the transition between an inspiration phase and an expiration phase is carried out by controlled deceleration of the turbine ( 2   a ).  
   
   
       11 . Process according to  claim 8 , characterized in that during expiration phases, an expiration valve ( 14 ) which is part of a third circuit ( 11 ) connected to the mask ( 4 ) or to the incubation device, is controlled, via a proportional electro-valve ( 15 ) and a second circuit ( 16 ), by a regulation member of the pressure in the first circuit ( 3 ).  
   
   
       12 . Process according to  claim 11 , characterized in that the computation means and the control means of the speed of rotation of the generator adapt the speed of the turbine ( 2   a ) as a function of a threshold of this expiration pressure beyond a regulated loss, by the expiration valve ( 14 ), so as to create a rinsing flow rate in the first circuit.  
   
   
       13 . Process according to  claim 8 , characterized in that during phases of insufflation corresponding to the inspiration phases, an expiration valve ( 14 ), which is part of a third circuit ( 11 ) connected to the mask ( 4 ) or to the intubation device, is controlled via a proportional electro-valve ( 15 ) and by a second circuit ( 16 ), according to pressure.  
   
   
       14 . Process according to  claim 8 , characterized in that it comprises a measurement of expiration flow rate and a measurement of inspiration flow rate.  
   
   
       15 . Device ( 1 ) for providing a respiratory gas to a patient according to respiratory cycles, comprising a gas flow generator ( 2 ) provided with a turbine ( 2   a ) for flow inertia and high nominal speed, a first circuit ( 3 ) called a circuit for supplying gaseous flow toward a respiratory mask ( 4 ) or an intubation means of the patient, means ( 5 ,  6 ,  7 ,  8 ) for measuring pressure and/or of flow rate of the gaseous flow, computation means ( 9 ) of parameters of pressure and/or flow rate, and means ( 10 ) for controlling the speed of rotation of the generator, characterized in that the measuring means ( 5 ,  6 ,  7 ,  8 ), the computation means ( 9 ) and the speed control means ( 10 ) coact automatically to control the speed of rotation of the turbine ( 2   a ) as a function of the inspiration and expiration phases and as a function of the patient pressure signals and/or inspiration flow rate signals, and in that the control system of the generator carries out phases of pressure increase with increasing slopes of pressure by means of acceleration of the turbine ( 2   a ), the supply of respiratory gas taking place according to pressure or according to volume.  
   
   
       16 . Device according to  claim 15 , characterized in that the control system of the generator carries out the transition between an inspiration phase and an expiration phase by means of controlled deceleration of the turbine ( 2   a ).  
   
   
       17 . Device according to  claim 15 , characterized in that the control system of the generator comprises means permanently adjusting the insufflation pressure between a low pressure threshold and a maximum pressure threshold so as to maintain the inspiration current volume as near as possible to a predetermined target volume.  
   
   
       18 . Device according to  claim 15 , characterized in that it comprises a proportional electro-valve ( 15 ), a second circuit ( 16 ) and an expiration valve ( 14 ), the proportional electro-valve ( 15 ) and the second circuit ( 16 ) being arranged to control the expiration valve ( 14 ) with a pressure regulating member of the first circuit ( 3 ) during expiration phases.  
   
   
       19 . Device according to  claim 15 , characterized in that computation means and the means for controlling the speed of rotation of the generator are arranged to adapt the speed of the turbine ( 2   a ) as a function of an expiration pressure threshold beyond a loss regulated by an expiration valve ( 14 ) so as to create a rinsing flow rate in the first circuit during expiration phases.  
   
   
       20 . Device according to  claim 18 , characterized in that the proportional electro-valve ( 15 ) and the second circuit ( 16 ) are arranged to control the expiration valve ( 14 ) according to pressure during insufflation phases corresponding to the inspiration phases.