Method and an apparatus for monitoring and controlling flows

A method for monitoring and controlling flows adapted for use in medical equipment including an anesthetic machine and a ventilator for influencing a patient's respiratory system, said equipment comprising a microprocessor, an airway system, several microprocessor-controlled valve state monitoring units and valve actuating units as well as sensor data collecting and receiving units, said airway system comprising drive gas conduits connecting an inhalation valve (2) and an exhalation valve (5) for gas-discharging as well as an equipment end flow sensor (3) for measuring the drive gas flow introduced or discharged through the inhalation valve and the exhalation valve;

• said airway system further comprising a patient end breathing tubing which is provided with a patient end flow sensor (11) for measuring flows of inspired and expired gases of the patient;
• said method comprising the following steps:
• A. the microprocessor actuates the airway system into an inhaling control period and an exhaling control period alternately through the valve actuating units;
• B. the microprocessor monitors control parameters of the inhalation valve (2) through the valve state monitoring units;
• C. the microprocessor acquires gas flow values monitored and measured by the equipment end flow sensor (3) and the patient end flow sensor (11) through the sensor data collecting and receiving units;
• D. the microprocessor analyzes and compares the control parameters with the respective gas flow values measured during a same inhaling control period or during a same exhaling control period, and carries out adjustment based on the analyzed and compared result.

An apparatus for monitoring and controlling flows adapted for use in medical equipment for influencing a patient's respiratory system, especially in an anesthetic machine and a ventilator, said apparatus comprising:

• an airway system, which comprises an inhalation valve (2) and an exhalation valve (5) installed in drive gas conduits, an equipment end flow sensor (3) for measuring the introduced and/or discharged drive gas flow through the inhalation valve (2) and/or the exhalation valve (5) and a patient end flow sensor (11) for measuring the patient's inspired and expired gas flow,
• valve state monitoring units and valve actuating units connected to the inhalation valve (2) and/or the exhalation valve (5),
• sensor data collecting and receiving units associated with the equipment end flow sensor (3) and the patient end flow sensor (11),
• a microprocessor for controlling the valve state monitoring units, the valve actuating units and the sensor data collecting and receiving units,
• wherein the microprocessor analyzes and compares the measured flow values of the equipment end flow sensor (3) and the patient end flow sensor (11) and with the control parameters of the inhalation valve (2) and/or the exhalation valve (5) and thereby determines and controls the operation states of the respective flow sensors and valves so as to control the flows accurately.