초록 ▼

In a device for measuring the breath volume of patients, a pair of temperature sensitive sensors are arranged in a tube-like housing of a respiration conduit of a respirator. The sensors are spaced from one another in flow direction and an air resistance member is arranged between them in such way t

In a device for measuring the breath volume of patients, a pair of temperature sensitive sensors are arranged in a tube-like housing of a respiration conduit of a respirator. The sensors are spaced from one another in flow direction and an air resistance member is arranged between them in such way that at least in one of the opposite air flow directions one of the sensors is in a position sheltered from the air flow by the air resistance member. Both of the sensors are connected with electronic circuits respectively and a current supply for holding the temperatures of the sensors on constant high levels. A calorimeter unit is connected to the circuits measuring the current supply necessary to compensate the temperature decrease of the sensors caused by the cool respiration flow. The air throughput is calculated in dependence on the measured current supply. Because in a predetermined flow direction the leeward sensor with respect to the air resistance member needs a lower current supply than the upstream sensor the calculating device provides different outputs for the pair of sensors whereby the flow direction can be determined and only the expiration air volume is indicated.

대표청구항 ▼

An improvement in a fluid flow measuring apparatus for detecting direction of flow and the magnitude thereof, the apparatus comprising a conduit, a pair of temperature sensors arranged in the conduit, a flow resistance member arranged between radial planes of said pair of temperature sensors and axi

An improvement in a fluid flow measuring apparatus for detecting direction of flow and the magnitude thereof, the apparatus comprising a conduit, a pair of temperature sensors arranged in the conduit, a flow resistance member arranged between radial planes of said pair of temperature sensors and axially aligned with one of said pair of temperature sensors and means for tending to maintain the temperature of each sensor at a predetermined high level above the temperature of the fluid, the improvement comprising an arrangement in which the other one of said pair of temperature sensors is radially offset with respect to the axial alignment plane intersecting the one temperature sensor and said flow resistance member.