Positive pressure breathing circuit

An a positive pressure breathing circuit for operation in conjunction with a positive pressure ventilator and interposed btween the ventilator and a patient-supported device such as a patient connection means, useful in conjunction with respiratory therapy, the improvement comprising in combination,

• a concentrically oriented inhalation/exhalation circuit having an inner inhalation tube and an outer exhalation tube, said outer exhalation tube being spaced from and concentrically oriented with respect to said inner inhalation tube positioned therein,
• said inner inhalation tube having a patient receiving terminal at one end thereof and a gas source terminal at the opposed end thereof in fluid communication with the positive pressurized source of said ventilator,
• said outer exhalation tube having a patient receiving terminal at one end thereof and an exhaust end at the opposed end thereof,
• said inner inhalation tube and said outer exhalation tube being in fluid communication with the ventilator during the inhalation and exhalation breathing cycles respectively,
• inflatable occlusion means interposed between said inner inhalation tube and said outer exhalation tube and in fluid communication with said positive pressurized source of said ventilator such that said inflatable during the inhalation phase occlusion means is alternatively inflatable and deflatable during the exhalation phase in response to fluid pressure from the source thereof,
• the gas flow in said inhalation tube being countercurrent with respect to the gas flow in said exhalation tube thereby to stabilize and maintain the temperature of the gas within said inner inhalation tube without any extraneous source of heat, while at the same time permitting inflation of said inflatable occlusion means during the inhalation cycle thereby to prevent the admixture of inhaled gases and exhaled gases during the inhalation cycle while concomitantly permitting the exhausting of exhaled gases through the system,
• said ventilator functioning to create a gas back pressure in the inhalation tube during the exhalation cycle thereby to force exhaled gases to exhaust from the system through the exhalation tube due to the fluid gas pressure created therein,
• whereby gas suitable for patient inhalation enters said circuit through said inner inhalation tube under positive pressure to be received by the patient during which time said inflatable occlusion means is fully inflated and interposed between said inner inhalation tube and said outer exhalation tube to prevent the admixture of inhaled gases with exhaled gases, while resisting any back pressure existing in said circuit, while exhaled gases exhaled by the patient are forced initially into said inhalation tube and are caused by the back pressure existing in said inhalation tube to exit through said exhalation tube, said occlusion means being deflated during the exhalation cycle to permit the exhausting of exhaled gases therethrough.