A fluid flow sensor includes a hollow cylindrical casing containing a large number of solid spheres of identical diameter, packed tightly together. Fluid inflow and fluid outflow blocks are mounted to opposite ends of the casing, forming a fluid-tight seal. The fluid inflow and outflow blocks each enclose a generally conical fluid chamber tapering from where it meets an end of an interior of the casing to a respective inlet passage or outlet passage. Circular grilles divide the casing from each fluid chamber and retain the spheres in place. A pressure differential across the casing is measured via side passages extending laterally from each fluid chamber. For a given fluid, a given casing diameter and a given sphere diameter, this pressure differential can be converted to a fluid flow rate.

An airway circuit has two modes of operation, dependent upon the presence or absence of a nebulizer in a nebulizer port. When the nebulizer if absent, a patient port is in fluid communications with a ventilation circuit port through a heat and humidity exchange element. When the nebulizer is inserted into the nebulizer port, the nebulizer port (and nebulizer), patient port, and ventilation circuit port are in fluid communications with each other and the heat and humidity exchange element is isolated, thereby protecting the heat and humidity exchange element from medicines emanating from the nebulizer. After the nebulizer is removed from the nebulizer port, the patient port is again placed in fluid communications with the ventilation circuit port through a heat and humidity exchange element.

A removable gas sensor module is provided for a therapeutic gas delivery device. The gas sensor module includes a sample chamber which receives a sample gas from the therapeutic gas delivery device. A gas detection unit includes a plurality of sensors operable to measure at least one property of the sample gas. The sensors include two or more of a gas detection sensor, a humidity sensor, a temperature sensor, or a combination thereof. The gas sensor module is self-contained within the therapeutic gas delivery device and swappable with another gas sensor module.

A method and device, for enriching a gas flow with an anesthetic, include a gas mixer (1), with gas inlets (2a, 2b) and one or more gas outlets (3a, 3b), and an anesthetic dispenser (4) connected to the one or more gas outlets. The anesthetic dispenser at least partially enriches the gas flow to provide a breathing gas flow enriched with anesthetic at a patient connector (5). A control valve (7a) is arranged fluidically in series with the anesthetic dispenser (4). The gas outlet is connected to the patient connector (5) via a gas channel (8), arranged fluidically parallel to the anesthetic dispenser (4) and in which at least another control valve (7b) is arranged. A control unit (6) actuates at least one control valve as a function of a desired value for an anesthetic concentration in the breathing gas flow to change anesthetic concentration at the patient connector (5).

The present disclosure generally relates to systems and methods for delivery of therapeutic gas to patients, using techniques to compensate for disruptions in breathing gas flow measurement, such as when breathing gas flow measurement is unavailable or unreliable. Such techniques include using historical breathing gas flow rate data, such as moving average flow rates, moving median flow rates and/or flow waveforms. At least some of these techniques can be used to ensure that interruption in therapeutic gas delivery is minimized or eliminated.

A method for measuring the anesthetic agent consumption in a ventilation system has a breathing circuit which contains a gas mixer (1) and an anesthetic agent metering device (2). The anesthetic agent quantity, which is consumed over a pregiven time interval in the ventilation system, is determined from the sum of the determined anesthetic gas volume flows in the ventilation system which are integrated over the pregiven time interval.

Described is an apparatus for monitoring nitric oxide delivery, wherein such apparatus comprises an indicator to inform a user of the apparatus when the flow of breathing gas rises above or falls below a predetermined level or range. Also described is a method of monitoring nitric oxide delivery, wherein the flow of breathing gas is measured and displayed. In some embodiments, an alert is provided when the flow of breathing gas rises above or falls below a predetermined level or range.

Anesthesia apparatus adapted for operating in one of a gas-dispensing mode and a gas-less simulation mode, and method of operating the anesthesia apparatus. A mode selection command is received from an input/output unit of the anesthesia apparatus. A control unit of the anesthesia apparatus selects one of a gas-dispensing mode and a gas-less simulation mode based on the received mode selection command. At least one gas control parameter is received from the input/output unit. When the gas-dispensing mode is selected, the control unit actuates gas dispensing means of the anesthesia apparatus based on the received at least one gas control parameter. When the gas-less simulation mode is selected, the control unit prevents actuation of the gas dispensing means, and transmits the at least one gas control parameter to a patient simulation system via a communication interface of the input/output unit.

Patient simulation system adapted for interacting with a medical apparatus, and method for operating the patient simulation system. A processing unit of the patient simulation system stores at least one physiological model of a patient in a memory of the patient simulation system. The processing unit receives at least one gas control parameter from the medical apparatus via a communication interface of the patient simulation system. The processing unit correlates the at least one gas control parameter with one of the at least one physiological model of a patient to generate simulated physiological effects. The processing unit further transmits the simulated physiological effects to the medical apparatus via the communication interface. In a particular aspect, the medical apparatus consists of an anesthesia apparatus.

The invention relates to a method of determining water level in a humidifier chamber that is part of a humidified gases delivery apparatus and system. The method comprising the steps of delivering power to a heater plate, varying the power delivered to the heater plate, measuring the rate of change of temperature and determining the level of water based on the heating characteristics of the volume of water within the chamber, in particular determining the level of water within the chamber based on the rate of change of temperature and the supplied power.