The design and structure of a physiological fluid collection bag with instant data transmission utilizing micromachined thermal time-of-flight flow sensing device as well as integrated pH value and density sensors for simultaneous and continuous measurement of the instant volumetric flow rate, accumulated total volume, pH value and density or specific gravity data of the collected fluid is disclosed in embodiments. The fluid collection bag includes a collection chamber and storage chamber wherein the sensing and measurement module is installed inside the storage chamber of the bag, for which it can be fully disposable. The fluid collection bag is able to metering the flow rate and instantly relay the data to the reusable data processing unit that can transmit the data to the designated data center or to the specified medical staffs.
