Humidifying means

Claim 1

An apparatus for humidifying and heating air to be breathed by a patient undergoing artificial respiration, comprising humidification and heating means to heat air to a suitable temperature which does not exceed, under steady operating conditions, the maximum desired temperature at which the air is to be admitted into the patient''s body, and to substantially saturate the air with water vapor at that output temperature; said humidification and heating means comprising a body portion having a first part thereof defining a water container adapted to be pressurized and adapted to have water introduced therein from time to time in use; and a second part cooperable with the first part for providing an air space above the level of water in the first part, external heating means for said first part, said first part being adapted to be maintained in thermal contact with said external heating means, and control means to sense the temperature of the water contained in said first part aNd control the external heating means to maintain the temperature of the water at the desired level, releasable clamping means clamping said first part to said external heating means to permit said first part to be removed from the external heating means for sterilization or other purposes, a heat conductive plate defining a tortuous path provided with suitably spaced convolutions defining a core with a central axis therethrough, said heat conductive plate being located partly in said first part and partly in said air space defined by the first and second parts; a water absorbent material disposed along the tortuous path defined by said heat conductive plate; said second part having first and second air passage defining means providing communication between the interior of the body portion and the exterior thereof, said first air passage defining means adapted to be put in flow communication with a patient and said second passage defining means being adapted to be connected with a source of gas, at least the entrance of said first air passage defining means constituting an air outlet being above water level and in flow communication with the core of the tortuous path, with said water absorbent material being partially immersed in water in the first part, said heat conductive plate arranged with its axis substantially vertical in use and also being partially immersed in water in the first part to provide a lower seal for said tortuous path, said conductive plate having a top surface substantially in sealing engagement with said first part so that substantially all the air passing in either of said first or second air passage defining means in the inlet passage can only leave via the other air passage defining means and after passing through said tortuous path during which it gains an increased heat and water vapor content.

Claim 2

An apparatus for humidifying and heating air to be breathed by a patient undergoing artificial respiration, comprising humidification and heating means to heat air to a suitable temperature which does not exceed, under steady operating conditions, the maximum desired temperature at which the air is to be admitted into the patient''s body, and to substantially saturate the air with water vapor at that output temperature; said humidification and heating means comprising a body portion having a first part thereof defining a water container adapted to be pressurized and adapted to have water introduced therein from time to time in use; and a second part cooperable with the first part for providing an air space above the level of water in the first part, external heating means for said first part, said first part being adapted to be maintained in thermal contact with said external heating means, and control means to sense the temperature of the water contained in said first part aNd control the external heating means to maintain the temperature of the water at the desired level, releasable clamping means clamping said first part to said external heating means to permit said first part to be removed from the external heating means for sterilization or other purposes, a heat conductive plate defining a tortuous path provided with suitably spaced convolutions defining a core with a central axis therethrough, said heat conductive plate being located partly in said first part and partly in said air space defined by the first and second parts; a water absorbent material disposed along the tortuous path defined by said heat conductive plate; said second part having first and second air passage defining means providing communication between the interior of the body portion and the exterior thereof, said first air passage defining means adapted to be put in flow communication with a patient and said second passage defining means being adapted to be connected with a source of gas, at least the entrance of said first air passage defining means constituting an air outlet being above water level and in flow communication with the core of the tortuous path, with said water absorbent material being partially immersed in water in the first part, said heat conductive plate arranged with its axis substantially vertical in use and also being partially immersed in water in the first part to provide a lower seal for said tortuous path, said conductive plate having a top surface substantially in sealing engagement with said first part so that substantially all the air passing in either of said first or second air passage defining means in the inlet passage can only leave via the other air passage defining means and after passing through said tortuous path during which it gains an increased heat and water vapor content.