Abstract: Pocket-size medical spirometer comprising a housing and a measurement unit (MU), for measuring rate of total flow when a user exhales through the spirometer. The MU comprises a fluidic jet oscillator adapted to generate oscillating flow with frequency dependent on the rate of flow therethrough. The MU is disposed within the housing so as to form a bypass flow path defined between an outer surface of the MU and an inner surface of the housing. A measurement flow path is defined through the fluidic jet oscillator, such that the total flow is divided into a bypass flow and a measurement flow, the latter being less than the former at least by an order of magnitude. The spirometer further comprises a pressure or velocity transducer and an electronic circuit adapted to derive the total flow rate or volume from the transducer signal.

Abstract: Pocket-size medical spirometer comprising a housing and a measurement unit (MU), for measuring rate of total flow when a user exhales through the spirometer. The MU comprises a fluidic jet oscillator adapted to generate oscillating flow with frequency dependent on the rate of flow therethrough. The MU is disposed within the housing so as to form a bypass flow path defined between an outer surface of the MU and an inner surface of the housing. A measurement flow path is defined through the fluidic jet oscillator, such that the total flow is divided into a bypass flow and a measurement flow, the latter being less than the former at least by an order of magnitude. The spirometer further comprises a pressure or velocity transducer and an electronic circuit adapted to derive the total flow rate or volume from the transducer signal.

Abstract: A fluidic gas metering system interposed in a line running from a gas source to a user site to meter the gas stream being supplied to the user in a broad flowrate range defined by a low flowrate band at the lower end of the range, a medium band at the middle of the range and a high band at the upper end thereof. The system includes an input chamber which receives a stream of pressurized gas from the source and an output chamber from which the gas is supplied to the user. Intercoupling the chambers are three gas flow channels. The first channel is defined by a first fluidic generator operative only when the flowrate of the gas lies in the low band to yield periodic pulses whose frequency is proportional thereto. The second channel is defined by a second fluidic generator operative only when the flowrate of the gas lies in the medium band to yield periodic pulses whose frequency is proportional thereto.

Abstract: A fluidic gas metering system interposed in a line running from a gas source to a user site to meter the gas stream being supplied to the user in a broad flowrate range defined by a low flowrate band at the lower end of the range, a medium band at the middle of the range and a high band at the upper end thereof. The system includes an input chamber which receives a stream of pressurized gas from the source and an output chamber from which the gas is supplied to the user. Intercoupling the chambers are three gas flow channels. The first channel is defined to by a first fluidic generator only when the flow rate of the gas lies in the low band to yield periodic pulses whose frequency is proportional thereto. The second channel is defined by a second fluidic generator operative only when the flowrate of the gas lies in the medium band to yield periodic pulses whose frequency is proportional thereto.