Substance delivery apparatus
AssigneeResMed Limited
InventorsMichel Calluaud, Victor Yerbury
Life of this patent
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Abstract
A substance delivery apparatus (10) for use with a system (12) for supplying breathable gas to a human or animal. The apparatus includes a mechanism (22) to measure the pressure of the supplied breathable gas (22) to detect inhalation by the human or animal; and elements (54, 56, 58, 60) to deliver the substance (52) to the human or animal during inhalation at a pressure higher than the supplied pressure of the breathable gas. A method of delivering a substance (52) is also disclosed.
Claims23
A substance delivery apparatus for use with a system for supplying breathable gas to a human or animal, said system including a pressurized gas flow generator in fluid communication with a mask worn by the human or animal via a flexible conduit, the apparatus including:
- an airflow sensor adapted to measure the volumetric flow rate of the breathable gas passing through the conduit and generate a first signal indicative of the breathable gas flow rate;
- a first amplifier to amplify the first input signal into a second input signal also indicative of the breathable gas flow rate;
- a differentiating filter to derive the first input signal into a third input signal indicative of acceleration or deceleration of the breathable gas and inhalation or exhalation respectively;
- a linear drive means;
- a positive displacement diaphragm pump displaced by the linear drive means to deliver the substance to the human or animal during inhalation at a pressure higher than the supplied pressure of the breathable gas;
- a pressure transducer connected to the conduit, the transducer being adapted to generate a fourth input signal indicative of the pressure of the supplied breathable gas;
- a second amplifier to amplify the fourth input signal into a fifth input signal also indicative of the breathable gas pressure;
- a first control system having input means adapted to allow the input of a predetermined sixth input signal indicative of the volume of the substance to be delivered and a predetermined seventh input signal indicative of the amount by which the pressure of the delivered substance is to exceed the pressure of the supplied breathable gas,
- wherein said first control system is adapted to receive the second, third, fifth, sixth and seventh input signals and calculate and generate a first output signal indicative of the amount of displacement of the linear drive means and a second output signal indicative of the direction of the displacement required to produce a negative or positive pumping pressure.
A method of delivering a substance to a human or animal being supplied with breathable gas, the method including the steps of:
- measuring the volumetric flow rate of the supplied breathable gas with an air flow sensor adapted to generate a first input signal indicative of the volumetric flow rate of the supplied breathable gas;
- amplifying the first input signal into a second input signal also indicative of the volumetric flow rate of the supplied breathable gas;
- differentiating the first input signal into a third input signal indicative of breathable gas acceleration or deceleration to detect inhalation or exhalation respectively;
- measuring the pressure of the supplied breathable gas with a pressure transducer adapted to generate a fourth input signal indicative of the pressure of the supplied breathable gas;
- amplifying the fourth input signal into a fifth input signal also indicative of the pressure of the supplied breathable gas;
- inputting the second, third, fourth, fifth input signals and a predetermined sixth input signal indicative of the volume of the substance to be delivered and a predetermined seventh input signal indicative of the amount by which the pressure of the delivered substance should exceed the pressure of the breathable gas into a first control system, the first control system adapted to generating a first output signal indicative of the amount of displacement of a linear drive means and a second output signal indicative of the direction of the displacement required to produce negative or positive pumping pressure;
- and
- delivering the substance to the human or animal during inhalation at a pressure higher than the supplied pressure of the breathable gas using a positive displacement diaphragm pump driven by the linear drive means.
Dependencies are inferred from the claim text.