Breathing circuits for medical respiratory devices which have an inspiratory conduit for delivery of respiration-related aeriform substances to a patient, may also have a expiratory conduit, and, in any case are arranged to communicate with a patient interface, such as a wye (14), and have heating means for respiration-related aeriform substances in at least the inspiratory conduit. The heating means may be a heated-liquid heating tube (11) within at least the inspiratory conduit or an electrical heating wire (38) on or in an inspiratory conduit comprising respiratory hose (37). The tube is in circulatory relationship with a heated-liquid reservoir (13) and is arranged internally to contain heated liquid (30) from the reservoir, and to transfer heat from the liquid--by radiation and conduction from the tube wall--to the substances in the conduit. This transferred heat tends to inhibit or to control formation of dangerous aqueous condensate from the substances by compensating heat losses they otherwise sustain, enhancing their capacity to retain water vapor and providing an intra-conduit environment in which the condensate is unlikely to form. A manifold (12) enables the tube to extend to the expiratory conduit.
The invention concerns an apparatus for supplying a respiratory gas and a method of controlling the apparatus. In accordance with the invention there is provided an apparatus for supplying a respiratory gas comprising a conveyor device for conveying the respiratory gas, a conduit means for feeding the respiratory gas conveyed by the conveyor device to a person, and a humidification device for humidifying the respiratory gas, which is distinguished by a sensor device for generating a signal indicative in respect of the respiratory gas humidity and a control device for controlling the humidification device having regard to the signal which is generated by the sensor device and which is indicative in respect of the respiratory gas humidity. Furthermore there is proposed a method of supplying a respiratory gas to a patient, in which the respiratory gas is introduced by means of a conveyor device into a conduit system leading to a patient and is humidified, wherein the conveyor device is operated in such a way that a respiratory gas pressure which is above ambient pressure obtains in the air conduit system, which is distinguished in that signals indicative in respect of the relative and/or absolute humidity of the respiratory gas are generated by means of a sensor device and the humidity of the respiratory gas is adjusted on the basis of the signals generated in that way.
A patient adapter for being connected to gas tubing in a ventilator circuit comprises of an inspiratory and an expiratory pipe, the latter having an internal diameter at least about 20% greater than the diameter of the inspiratory pipe. The invention also includes a respirator circuit in which an expiratory limb has an internal diameter at least about 20% greater than the diameter than the inspiratory tubing limb.
A pressure regulator for regulating the expiratory flow in a CPAP system includes submerging a tube into a column of water. Improvements are included for adjusting the level to which the tube is submerged and for ensuring constant water level.
An apparatus for delivering anaesthetic to human or animal patients. The apparatus is an anaesthetic machine which is arranged to mount components of an anaesthetic delivery circuit, and which includes a collector arrangement in the form of a manifold having a plurality of inlets and outlets. The manifold enables a reduction in the number of tubes connecting the various components in an anaesthetic system, which are normally required in prior art anaesthetic machines. The manifold also includes an arrangement which provides a Venturi effect on gas flow, and enables a pressure gauge to be mounted out of a patient breathing circuit. The machine is preferably portable.
An inspiratory tube intended to serve as at least part of an inspiratory line in a ventilator, has a tube wall, a distal end, a proximal end, a gas flow channel for carrying a flow of breathing gas and an opening in the wall at a specific distance from one end of the inspiratory tube, this opening being adapted for connection to an expiratory device (40). The inspiratory tube has a constriction in the gas flow channel between distal end of the inspiratory tube and the opening, a first channel that proceeds within the tube wall, generally parallel to the gas flow channel, and which opens into the gas flow channel between the distal end of the inspiratory tube and the constriction, and a second channel that proceeds within the wall, generally parallel to the gas flow channel, which opens into the gas flow channel between the constriction and the opening. The channels can be connected to a pressure gauge for determining the rate of flow and pressure of gas flowing in the gas flow channel.
