SU1281248A1 - Apparatus for measuring the rate of lung ventilation - Google Patents

Abstract

The invention relates to determining the flow of inhaled and exhaled air according to the speed of the pulmonary ventilation and allows to improve the measurement accuracy by ensuring the registration of the high-frequency components of the flow. The device contains a temperature compensation unit 1, a thermo-anemometric converter 2, a temperature control element 3. Unit 1 consists of a current source 5, resistors 7, 8 and 9, reference elements 10 and 13, drivers 11 and 14, RS flip-flop 12, key 6 and element 15 of the initial installation. When the thermistor of the transducer 2 is heated, the difference in voltage at the input of the element 10 changes the polarity of the signal when the thermoresistor switches the upper preset temperature level by a certain amount (for example, 0.02 ° C). In this case, the switch 6 is closed and controlled cooling of the thermistor to the lower predetermined temperature level occurs. When the thermistor is cooled below a predetermined level by a certain amount (for example, 0.1 ° C), the polarity of the signal at the output of element 13 changes. The recorder records the duration of the heating-cooling cycles in the measurement mode of pulse periods or the duration of cooling phases in the measurement mode. pulse duration with high accuracy. 1 il. with (L

Description

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The invention relates to medicine and concerns the determination of breathing parameters associated with the flow of inhaled and exhaled air and measured by the speed of pulmonary ventilation.

The aim of the invention is to improve the measurement accuracy by ensuring the detection of high-frequency flux components.

The drawing shows the functional diagram of the device.

The device for measuring the speed of pulmonary ventilation contains temperature compensation unit 1 connected in series, thermo-anemometric transducer 2, temperature control element 3, the output of which is connected to a common bus, and the input is connected to the input of temperature compensation unit 1, the second output of which is connected to registration unit 4.

The temperature compensation unit 1 contains a current source 5 connected in series, a switch 6, a first resistor 7, a second resistor 8, a third resistor 9, the output of which is connected to a common busbar, connected in series the first comparison element 10, the first driver 11, RS trigger 12, my output is the second output of the temperature compensation unit 1, and the inverse output is connected to the control input of the key 6, the second comparison element 13, the second driver 14, the initial setting element 15, the ballast resistor 16, and the second input driver 14 is connected to the output of the second comparison element 13, and the output is connected to the output of the initial installation element 15 and the second input of the RS flip-flop 12, the first inputs of the first comparison element 10 and the second comparison element 13 are connected to the input of the temperature compensation unit 1, the second input of the first element 10 comparisons are connected to a common point of resistors 7 and 8, the second input of the second comparison element 13 is connected to a common point of resistors 8 and 9. A ballast resistor 16 is connected between the input and output of switch 6 connected to the first output of block 1 ensatsii.

The device works as follows.

Before starting the measurements, the trigger 12 is reset with the element 15 of the initial setup. In this case, the key 6 associated with the corresponding output of the trigger 12 (in the initial zero state of the trigger 12 is an inverse output), closes the ballast resistor 16 to the thermistor of the thermo-anemometric converter 2 and shunts the maximum operating current. The thermistor starts to heat up intensely. In this case, the difference in voltage at the inputs

the comparison element 10 is determined by the ratio of the resistance values of the elements forming the bridge,, /, (). When the thermistor switches to the upper set temperature level

the value (-f-0.02 ° C) at the output of the comparison element 10 changes the polarity of the signal, which causes a change in the state of trigger 12 to the opposite. In this case, the key 6 is opened and the thermistor is applied to

measuring current. Controlled cooling of the thermistor to the lower preset temperature level is performed. At the same time, the difference in voltage at the inputs of the comparison element 13 is determined by the ratio of the resistance values of the elements forming the bridge Rz, Rz, (), RQ- When the thermoresistor switches the lower preset temperature level to the specified value (-0.1 ° С) at the output of the element 13 comparison, the polarity of the signal changes

returns trigger 12 to its original state. The measurement cycle is repeated. The registration unit 4, being connected to the output of the trigger 12, registers the duration of the heating-cooling cycles (in the measurement mode of the pulse following periods). However, when the trigger 12 is connected to the forward output (with the initial zero state of the trigger 12), the registration unit 4 registers the duration of only the cooling stages of the thermistor (in the pulse duration measurement mode).

Claims (1)

Invention Formula A device for measuring the speed of pulmonary ventilation, containing a temperature compensation unit connected in series, a thermo-anemometric transducer, a temperature control element whose output is connected to a common bus, and the input is connected to the input of a temperature compensation unit whose second output is connected to a recording unit, characterized in that , in order to improve the measurement accuracy, b.yuk temperature compensation contains a series-connected current source, switch, first, second and third resistor, the output to The first is connected to the common bus, the first reference element is connected in series, the first driver, the RS flip-flop, whose direct output is the second output of the block, and the inverse output is connected to the control input of the key, the second comparison element, the second driver, the initial setting element, a ballast resistor, the second driver's input connected to the output of the second comparison element, and the output to the output of the initial setup element and the second input of the RS flip-flop, the first inputs of the first and second comparison elements enes to the block input, a second input of the first element 1281248 34 comparison is connected to the common point of the primary and the third resistors, the ballast and a second resistor, the second input of the second resistor is connected between the input and the output Comparison element — with a common WTO key point, which is the first output of a block.