Abstract: A variable volume ratio compound counterlung is disclosed for use with a semi-closed circuit breathing apparatus. The compound counterlung generally comprises a flexible bag member disposed within an outer counterlung member. The flexible bag member and the outer counterlung member are in communication with an exhaled gas area of a breathing loop. The flexible bag member having first and second ends which are attached to said outer counterlung. A pair of depth sensors operatively associated with the flexible bag member are provided to vary the volume of said flexible bag member with changes in depth. The flexible bag member is driven by the outer counterlung to discharge gas stored within the flexible bag member depending on the diver's respiratory minute volume. The collapsing of said outer counterlung member also returns gas stored within the outer counterlung back into the breathing loop.

Abstract: An anaesthetic machine has a gas flow system with a variable-volume gas container for breathing gas, a fresh gas system for supplying the fresh gas system with a flow of fresh gas and a control unit. The control unit controls the variable-volume gas container during a first phase of inspiration so that a flow of breathing gas is released and mixes with a flow of fresh gas from the fresh gas system. The control unit starts a second phase of inspiration if the flow of breathing gas from the variable-volume gas container ceases before inspiration has been completed. The control unit controls the anaesthetic machine during said second phase so that inspiration is maintained with a flow of fresh gas from the fresh gas system in order to achieve a system in which all breathing modes can be accommodated and gas consumption is minimized.

Abstract: A balanced breathing loop for a rebreather is disclosed which includes a system of components that interact to provide substantial safety and alarm awareness benefits over existing methodology in recirculating breathing apparatus loops. The device relies on a specific arrangement of components to create both automatic alternate delivery of gas to replace metabolized oxygen in case of single component failures and breathing characteristic changes that warn the user that a component failure has occurred. The breathing characteristic changes allow the user to identify which specific component has failed, thus allowing for immediate corrective action.

Abstract: An apparatus for delivering a highly concentrated mixture of aerosolized liquid and pressurized gas to a patient including a collapsible membrane defining a chamber, the membrane further defining a first opening and a second opening in communication with the chamber. A mask defining an enclosure having a first passageway in communication with the first opening. A nebulizer having a body defining a reservoir for holding the liquid therein, the body including an inlet orifice and an outlet orifice which communicates with the second opening. A pressurized gas source which contains a pressurized gas with the pressurized gas source being in communication with the inlet orifice for providing the pressurized gas to the nebulizer. When the pressurized gas from the pressurized gas source enters the nebulizer, the pressurized gas mixes to form a mixture with the liquid inside the reservoir of the nebulizer.

Abstract: An anesthetic apparatus has a control unit and a breathing circuit with a connector for fresh gas, a bellows system and an outlet valve. The anesthetic apparatus operates at least as an open system, the connector then constituting an inspiratory part of the breathing circuit and the bellows system and outlet valve constituting an expiratory part of the breathing circuit. In order to reduce the adverse impact of compressible volume in the expiratory section on the functioning of the anesthetic apparatus, the control unit regulates the bellows system during inspiration so that a counter pressure, largely corresponding to the pressure of fresh gas at the connector, is maintained in the expiratory section of the breathing circuit.

Abstract: An improved manual pump is disclosed. The manual pump comprises a pair of side plates (10), a flexible cylindrical wall (15), a pump chamber (21), an axial shaft (11), a coil spring (12) and a pair of handle bars (16) secured to the side plates (10). When the handle bars (16) are grabbed and clutched with a hand, the side walls (10) are turned in opposite directions, twisting the pump chamber (21) to discharge fluid. The coil spring (12) assists to restore the original shape of the pump chamber (21) to charge fluid.

Abstract: A variable volume ratio compound counterlung is disclosed for use with a semi-closed circuit breathing apparatus. The compound counterlung generally comprises a flexible bag member disposed within an outer counterlung member. The flexible bag member and the outer counterlung member are in communication with an exhaled gas area of a breathing loop. The flexible bag member having first and second ends which are attached to said outer counterlung. A pair of depth sensors operatively associated with the flexible bag member are provided to vary the volume of said flexible bag member with changes in depth. The flexible bag member is driven by the outer counterlung to discharge gas stored within the flexible bag member depending on the diver's respiratory minute volume. The collapsing of said outer counterlung member also returns gas stored within the outer counterlung back into the breathing loop.

Abstract: A bellows arrangement for a ventilator/anesthesia system has a rigid container in which a bellows is arranged. The first end of the bellows is fastened to one end of the container, and the other end is displaceable relative to the first end. The container is connected to a propellant source of the ventilator/anesthesia system, and the bellows is in gaseous communication with a respiratory circuit of the ventilator/anesthesia system at the first end. In order to insure that the bellows always moves smoothly in a simple and inexpensive fashion, the second end of the bellows is provided with a guidance fixture which is connected to the container in every position of the second end so that, in an expansion or compression of the bellows, the second end is always displaced along the center axis while remaining substantially of the bellows parallel to the first end.

Abstract: A method and arrangement in connection with a ventilator, in which fresh gas is supplied to a patient and part of the patient's breathing gas is supplied to the patient with a bellows means. To provide a basic solution suitable for a variety of uses fresh gas is supplied to the patient by means of a gas mixer. The fresh gas flow from the gas mixer is occasionally led to drive the bellows means.