High-frequency artificial respirator

A high-frequency artificial respirator comprising:

• a patient circuit for delivering a first respiration gas to an air passage of a patient, the first respiration gas being supplied from a respiration gas source;
• oscillation generation means connected to said patient circuit for imparting a high-frequency oscillation to said first respiration gas in said patient circuit;
• means for low-pass filtering slowly varying gas components, said means for low-pass filtering including an essentially closed chamber having one input opening for connection with said patient circuit and having one output opening in communication with ambient atmosphere;
• and
• means for positive pressure generation being interfaced and communicating with said means for low-pass filtering slowly varying gas components, said means for positive pressure generation including a nozzle disposed in the vicinity of said one output opening in said chamber, for injecting a second gas through said output opening into said chamber to thereby generate a positive pressure within said chamber, wherein the low-pass filtering means and positive pressure generation means are integrally formed and include a bottom plate, a top plate and partition walls defining a serpentine gas passage interposed between the top and bottom plates, the nozzle of the positive pressure generation means being disposed within the gas passage and having an injection tip positioned in a direction opposite to that of the flow of air exhaled by the patient, the low-pass filtering means and positive pressure generation means further defining the serpentine gas passage with the first open end upstream of the gas passage for connection to the patient circuit and a second open end downstream of the gas passage which is open to the atmosphere, the nozzle being disposed between the first and second open ends of the serpentine passage.

A high-frequency artificial respirator comprising:

• a patient circuit for delivering a first respiration gas to an air passage of a patient, the first respiration gas being supplied from a respiration gas source;
• oscillation generation means connected to said patient circuit for imparting a high-frequency oscillation to said first respiration gas in said patient circuit;
• means for low-pass filtering slowly varying gas components, said means for low-pass filtering including an essentially closed chamber having one input opening for connection with said patient circuit and having one output opening in communication with ambient atmosphere;
• means for positive pressure generation being interfaced and communicating with said means for low-pass filtering slowly varying gas components, said means for positive pressure generation including a nozzle disposed in the vicinity of said one output opening in said chamber, for injecting a second gas through said output opening into said chamber to thereby generate a positive pressure within said chamber;
• a pressure sensor coupled to the patient circuit;
• a pressure measurement fluid line coupling the pressure sensor to the patient circuit;
• and
• a circuit for protecting the pressure sensor from moisture within the patient circuit, the pressure sensor protecting circuit including a fluid regulator, a pressure switch and a fluid resistor, the regulator, pressure switch and fluid resistor being coupled together in series and being interposed between the source of gas and the pressure measurement fluid line coupling the pressure sensor to the patient circuit, the pressure sensor protecting circuit providing a constant gas pressure to the pressure measurement fluid line and providing a flow of gas in the pressure measurement fluid line in a direction from the pressure sensor to the patient circuit.