公开(公告)号：US3645133A

公开(公告)日：1972-02-29

申请号：US3645133D

申请日：1970-04-15

Applicant: METROPHYSICS INC

Inventor： SIMETH PETER G ,  SEELEY RICHARD C

IPC: A61B5/087 ,  G01F1/68 ,  G01F1/00 ,  G01P5/10

CPC classification number: A61B5/0878 ,  G01F1/68

Abstract: An electronic spirometer having an accurate indication of exhaled tidal or minute volume. In the preferred embodiment, an adapter fits on the exhalation port of the breathing circle and monitors a patient''s exhaled volume when being ventilated. A heated thermistor mounted in the adapter senses the gas flow as an approximate fourth power function of the current necessary to maintain the thermistor at a constant temperature. A signal conditioner provides the current required to keep the thermistor at a constant temperature and converts the nonlinear heater current into a signal which is proportional to flow. A second thermistor in the probe corrects for temperature variations. The output of the signal conditioner is fed into the integrator circuit which converts the flow signal to a volume signal. In the minute volume mode, a clock generates a command signal every 30 seconds. This transfers the integrator output into a readout unit and resets the integrator to zero. In the tidal volume mode, the flow is integrated on a breath by breath basis and the volume signal is read out when the exhaled flow reaches zero. Outputs are provided for recording the flow rate and the minute integrated volume. An alarm system is provided for indicating when minute volume limits are too low or too high.

Abstract translation: 具有呼出潮气或微小体积的精确指示的电子肺活量计。 在优选实施例中，适配器适合于呼吸圈的呼出口，并且在通气时监测患者的呼出量。 安装在适配器中的加热热敏电阻感测气流作为将热敏电阻保持在恒定温度所需的电流的大致第四功率函数。 信号调节器提供将热敏电阻保持在恒定温度所需的电流，并将非线性加热器电流转换成与流量成比例的信号。 探头中的第二个热敏电阻校正温度变化。 信号调节器的输出被馈送到积分器电路，其将流量信号转换成音量信号。 在分钟音量模式下，时钟每30秒产生一个指令信号。 这将积分器输出传输到读出单元，并将积分器复位为零。 在潮气量模式中，气流通过呼吸进行积分，当呼出流量达到零时，体积信号被读出。 提供输出用于记录流量和分集成体积。 提供了一个报警系统，用于指示何时微小的音量限制太低或太高。